gecko-dev/dom/base/Document.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * Base class for all our document implementations.
 */

#include "AudioChannelService.h"
#include "mozilla/dom/Document.h"
#include "DocumentInlines.h"
#include "mozilla/AnimationComparator.h"
#include "mozilla/AntiTrackingCommon.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/BinarySearch.h"
#include "mozilla/CSSEnabledState.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/EffectSet.h"
#include "mozilla/EnumSet.h"
#include "mozilla/IdentifierMapEntry.h"
#include "mozilla/IntegerRange.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Likely.h"
#include "mozilla/PresShell.h"
#include "mozilla/PresShellInlines.h"
#include "mozilla/RestyleManager.h"
#include "mozilla/StaticPrefs.h"
#include "mozilla/URLExtraData.h"
#include <algorithm>

#include "mozilla/Logging.h"
#include "plstr.h"
#include "mozilla/Sprintf.h"

#include "mozilla/Telemetry.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsILoadContext.h"
#include "nsITextControlFrame.h"
#include "nsNumberControlFrame.h"
#include "nsUnicharUtils.h"
#include "nsContentList.h"
#include "nsCSSPseudoElements.h"
#include "nsIObserver.h"
#include "nsIBaseWindow.h"
#include "nsILayoutHistoryState.h"
#include "nsLayoutStylesheetCache.h"
#include "mozilla/css/Loader.h"
#include "mozilla/css/ImageLoader.h"
#include "nsDocShell.h"
#include "nsDocShellLoadTypes.h"
#include "nsIDocShellTreeItem.h"
#include "nsCOMArray.h"
#include "nsQueryObject.h"
#include "mozilla/Services.h"
#include "nsScreen.h"
#include "ChildIterator.h"

#include "mozilla/AsyncEventDispatcher.h"
#include "mozilla/BasicEvents.h"
#include "mozilla/EventListenerManager.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/FullscreenChange.h"
#include "mozilla/PendingAnimationTracker.h"

#include "mozilla/dom/Attr.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/FeaturePolicy.h"
#include "mozilla/dom/FramingChecker.h"
#include "mozilla/dom/HTMLSharedElement.h"
#include "mozilla/dom/Navigator.h"
#include "mozilla/dom/Performance.h"
#include "mozilla/dom/TreeOrderedArrayInlines.h"
#include "mozilla/dom/ResizeObserver.h"
#include "mozilla/dom/ResizeObserverController.h"
#include "mozilla/dom/ServiceWorkerContainer.h"
#include "mozilla/dom/ScriptLoader.h"
#include "mozilla/dom/ShadowIncludingTreeIterator.h"
#include "mozilla/dom/StyleSheetList.h"
#include "mozilla/dom/SVGUseElement.h"
#include "mozilla/net/CookieSettings.h"
#include "nsGenericHTMLElement.h"
#include "mozilla/dom/CDATASection.h"
#include "mozilla/dom/ProcessingInstruction.h"
#include "nsDOMString.h"
#include "nsNodeUtils.h"
#include "nsLayoutUtils.h"  // for GetFrameForPoint
#include "nsIFrame.h"
#include "nsIBrowserChild.h"

#include "nsRange.h"
#include "mozilla/dom/DocumentType.h"
#include "mozilla/dom/NodeIterator.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/PromiseNativeHandler.h"
#include "mozilla/dom/TreeWalker.h"

#include "nsIServiceManager.h"
#include "mozilla/dom/ServiceWorkerManager.h"
#include "imgLoader.h"

#include "nsAboutProtocolUtils.h"
#include "nsCanvasFrame.h"
#include "nsContentCID.h"
#include "nsError.h"
#include "nsPresContext.h"
#include "nsThreadUtils.h"
#include "nsNodeInfoManager.h"
#include "nsIFileChannel.h"
#include "nsIMultiPartChannel.h"
#include "nsIRefreshURI.h"
#include "nsIWebNavigation.h"
#include "nsIScriptError.h"
#include "nsISimpleEnumerator.h"
#include "nsIRequestContext.h"
#include "nsStyleSheetService.h"

#include "nsNetUtil.h"  // for NS_NewURI
#include "nsIInputStreamChannel.h"
#include "nsIAuthPrompt.h"
#include "nsIAuthPrompt2.h"

#include "nsIScriptSecurityManager.h"
#include "nsIPermissionManager.h"
#include "nsIPrincipal.h"
#include "nsIPrivateBrowsingChannel.h"
#include "ExpandedPrincipal.h"
#include "mozilla/NullPrincipal.h"

#include "nsIDOMWindow.h"
#include "nsPIDOMWindow.h"
#include "nsFocusManager.h"
#include "nsICookiePermission.h"
#include "nsICookieService.h"

#include "nsBidiUtils.h"

#include "nsContentCreatorFunctions.h"

#include "nsIScriptContext.h"
#include "nsBindingManager.h"
#include "nsHTMLDocument.h"
#include "nsIRequest.h"
#include "mozilla/dom/BlobURLProtocolHandler.h"

#include "nsCharsetSource.h"
#include "nsIParser.h"
#include "nsIContentSink.h"

#include "mozilla/EventDispatcher.h"
#include "mozilla/EventStates.h"
#include "mozilla/InternalMutationEvent.h"
#include "nsDOMCID.h"

#include "jsapi.h"
#include "nsIXPConnect.h"
#include "xpcpublic.h"
#include "nsCCUncollectableMarker.h"
#include "nsIContentPolicy.h"
#include "nsContentPolicyUtils.h"
#include "nsICategoryManager.h"
#include "nsIDocumentLoaderFactory.h"
#include "nsIDocumentLoader.h"
#include "nsIContentViewer.h"
#include "nsIXMLContentSink.h"
#include "nsIPrompt.h"
#include "nsIPropertyBag2.h"
#include "mozilla/dom/PageTransitionEvent.h"
#include "mozilla/dom/StyleRuleChangeEvent.h"
#include "mozilla/dom/StyleSheetChangeEvent.h"
#include "mozilla/dom/StyleSheetApplicableStateChangeEvent.h"
#include "nsJSUtils.h"
#include "nsFrameLoader.h"
#include "nsEscape.h"
#include "nsObjectLoadingContent.h"
#include "nsHtml5TreeOpExecutor.h"
#include "mozilla/dom/HTMLFormElement.h"
#include "mozilla/dom/HTMLLinkElement.h"
#include "mozilla/dom/HTMLMediaElement.h"
#include "mozilla/dom/HTMLIFrameElement.h"
#include "mozilla/dom/HTMLImageElement.h"
#include "mozilla/dom/HTMLTextAreaElement.h"
#include "mozilla/dom/MediaSource.h"

#include "mozAutoDocUpdate.h"
#include "nsGlobalWindow.h"
#include "mozilla/Encoding.h"
#include "nsDOMNavigationTiming.h"

#include "mozilla/SMILAnimationController.h"
#include "imgIContainer.h"
#include "nsSVGUtils.h"

#include "nsRefreshDriver.h"

// FOR CSP (autogenerated by xpidl)
#include "nsIContentSecurityPolicy.h"
#include "mozilla/dom/nsCSPContext.h"
#include "mozilla/dom/nsCSPService.h"
#include "mozilla/dom/nsCSPUtils.h"
#include "nsHTMLStyleSheet.h"
#include "nsHTMLCSSStyleSheet.h"
#include "mozilla/dom/DOMImplementation.h"
#include "mozilla/dom/ShadowRoot.h"
#include "mozilla/dom/Comment.h"
#include "nsTextNode.h"
#include "mozilla/dom/Link.h"
#include "mozilla/dom/HTMLCollectionBinding.h"
#include "mozilla/dom/HTMLElementBinding.h"
#include "nsXULAppAPI.h"
#include "mozilla/dom/Touch.h"
#include "mozilla/dom/TouchEvent.h"
#include "ReferrerInfo.h"

#include "mozilla/Preferences.h"

#include "imgILoader.h"
#include "imgRequestProxy.h"
#include "nsWrapperCacheInlines.h"
#include "nsSandboxFlags.h"
#include "mozilla/dom/AnimatableBinding.h"
#include "mozilla/dom/AnonymousContent.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/ClientInfo.h"
#include "mozilla/dom/ClientState.h"
#include "mozilla/dom/DocumentFragment.h"
#include "mozilla/dom/DocumentL10n.h"
#include "mozilla/dom/DocumentTimeline.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/HTMLBodyElement.h"
#include "mozilla/dom/HTMLInputElement.h"
#include "mozilla/dom/ImageTracker.h"
#include "mozilla/dom/MediaQueryList.h"
#include "mozilla/dom/NodeFilterBinding.h"
#include "mozilla/OwningNonNull.h"
#include "mozilla/dom/BrowserChild.h"
#include "mozilla/dom/WebComponentsBinding.h"
#include "mozilla/dom/CustomElementRegistryBinding.h"
#include "mozilla/dom/CustomElementRegistry.h"
#include "mozilla/dom/ServiceWorkerDescriptor.h"
#include "mozilla/dom/TimeoutManager.h"
#include "mozilla/ExtensionPolicyService.h"
#include "nsFrame.h"
#include "nsDOMCaretPosition.h"
#include "nsViewportInfo.h"
#include "mozilla/StaticPtr.h"
#include "nsITextControlElement.h"
#include "nsIEditor.h"
#include "nsIHttpChannelInternal.h"
#include "nsISecurityConsoleMessage.h"
#include "nsCharSeparatedTokenizer.h"
#include "mozilla/dom/XPathEvaluator.h"
#include "mozilla/dom/XPathNSResolverBinding.h"
#include "mozilla/dom/XPathResult.h"
#include "nsIDocumentEncoder.h"
#include "nsIDocumentActivity.h"
#include "nsIStructuredCloneContainer.h"
#include "nsIMutableArray.h"
#include "mozilla/dom/DOMStringList.h"
#include "nsWindowSizes.h"
#include "mozilla/dom/Location.h"
#include "mozilla/dom/FontFaceSet.h"
#include "gfxPrefs.h"
#include "nsISupportsPrimitives.h"
#include "mozilla/ServoStyleSet.h"
#include "mozilla/StyleSheet.h"
#include "mozilla/StyleSheetInlines.h"
#include "mozilla/dom/SVGDocument.h"
#include "mozilla/dom/SVGSVGElement.h"
#include "mozilla/dom/DocGroup.h"
#include "mozilla/dom/TabGroup.h"
#ifdef MOZ_XUL
#  include "mozilla/dom/XULBroadcastManager.h"
#  include "mozilla/dom/XULPersist.h"
#  include "nsIXULWindow.h"
#  include "nsIChromeRegistry.h"
#  include "nsXULPrototypeDocument.h"
#  include "nsXULCommandDispatcher.h"
#  include "nsXULPopupManager.h"
#  include "nsIDocShellTreeOwner.h"
#endif
#include "mozilla/dom/BoxObject.h"

#include "mozilla/DocLoadingTimelineMarker.h"

#include "mozilla/dom/WindowGlobalChild.h"

#include "nsISpeculativeConnect.h"

#include "mozilla/MediaManager.h"

#include "AutoplayPolicy.h"
#include "nsIURIMutator.h"
#include "mozilla/DocumentStyleRootIterator.h"
#include "mozilla/PendingFullscreenEvent.h"
#include "mozilla/RestyleManager.h"
#include "mozilla/ClearOnShutdown.h"
#include "nsHTMLTags.h"
#include "MobileViewportManager.h"
#include "NodeUbiReporting.h"
#include "nsICookieService.h"
#include "mozilla/net/ChannelEventQueue.h"
#include "mozilla/net/RequestContextService.h"
#include "StorageAccessPermissionRequest.h"
#include "mozilla/dom/WindowProxyHolder.h"
#include "ThirdPartyUtil.h"

#define XML_DECLARATION_BITS_DECLARATION_EXISTS (1 << 0)
#define XML_DECLARATION_BITS_ENCODING_EXISTS (1 << 1)
#define XML_DECLARATION_BITS_STANDALONE_EXISTS (1 << 2)
#define XML_DECLARATION_BITS_STANDALONE_YES (1 << 3)

extern bool sDisablePrefetchHTTPSPref;

mozilla::LazyLogModule gPageCacheLog("PageCache");

namespace mozilla {
namespace dom {

typedef nsTArray<Link*> LinkArray;

static LazyLogModule gDocumentLeakPRLog("DocumentLeak");
static LazyLogModule gCspPRLog("CSP");
LazyLogModule gUserInteractionPRLog("UserInteraction");

static nsresult GetHttpChannelHelper(nsIChannel* aChannel,
                                     nsIHttpChannel** aHttpChannel) {
  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aChannel);
  if (httpChannel) {
    httpChannel.forget(aHttpChannel);
    return NS_OK;
  }

  nsCOMPtr<nsIMultiPartChannel> multipart = do_QueryInterface(aChannel);
  if (!multipart) {
    *aHttpChannel = nullptr;
    return NS_OK;
  }

  nsCOMPtr<nsIChannel> baseChannel;
  nsresult rv = multipart->GetBaseChannel(getter_AddRefs(baseChannel));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  httpChannel = do_QueryInterface(baseChannel);
  httpChannel.forget(aHttpChannel);

  return NS_OK;
}

}  // namespace dom

#define NAME_NOT_VALID ((nsSimpleContentList*)1)

IdentifierMapEntry::IdentifierMapEntry(
    const IdentifierMapEntry::AtomOrString& aKey)
    : mKey(aKey) {}

IdentifierMapEntry::IdentifierMapEntry(
    const IdentifierMapEntry::AtomOrString* aKey)
    : mKey(aKey ? *aKey : nullptr) {}

IdentifierMapEntry::~IdentifierMapEntry() {}

IdentifierMapEntry::IdentifierMapEntry(IdentifierMapEntry&& aOther)
    : PLDHashEntryHdr(std::move(aOther)),
      mKey(std::move(aOther.mKey)),
      mIdContentList(std::move(aOther.mIdContentList)),
      mNameContentList(std::move(aOther.mNameContentList)),
      mChangeCallbacks(std::move(aOther.mChangeCallbacks)),
      mImageElement(std::move(aOther.mImageElement)) {}

void IdentifierMapEntry::Traverse(
    nsCycleCollectionTraversalCallback* aCallback) {
  NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                     "mIdentifierMap mNameContentList");
  aCallback->NoteXPCOMChild(static_cast<nsINodeList*>(mNameContentList));

  if (mImageElement) {
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mIdentifierMap mImageElement element");
    nsIContent* imageElement = mImageElement;
    aCallback->NoteXPCOMChild(imageElement);
  }
}

bool IdentifierMapEntry::IsEmpty() {
  return mIdContentList->IsEmpty() && !mNameContentList && !mChangeCallbacks &&
         !mImageElement;
}

bool IdentifierMapEntry::HasNameElement() const {
  return mNameContentList && mNameContentList->Length() != 0;
}

void IdentifierMapEntry::AddContentChangeCallback(
    Document::IDTargetObserver aCallback, void* aData, bool aForImage) {
  if (!mChangeCallbacks) {
    mChangeCallbacks = new nsTHashtable<ChangeCallbackEntry>;
  }

  ChangeCallback cc = {aCallback, aData, aForImage};
  mChangeCallbacks->PutEntry(cc);
}

void IdentifierMapEntry::RemoveContentChangeCallback(
    Document::IDTargetObserver aCallback, void* aData, bool aForImage) {
  if (!mChangeCallbacks) return;
  ChangeCallback cc = {aCallback, aData, aForImage};
  mChangeCallbacks->RemoveEntry(cc);
  if (mChangeCallbacks->Count() == 0) {
    mChangeCallbacks = nullptr;
  }
}

void IdentifierMapEntry::FireChangeCallbacks(Element* aOldElement,
                                             Element* aNewElement,
                                             bool aImageOnly) {
  if (!mChangeCallbacks) return;

  for (auto iter = mChangeCallbacks->ConstIter(); !iter.Done(); iter.Next()) {
    IdentifierMapEntry::ChangeCallbackEntry* entry = iter.Get();
    // Don't fire image changes for non-image observers, and don't fire element
    // changes for image observers when an image override is active.
    if (entry->mKey.mForImage ? (mImageElement && !aImageOnly) : aImageOnly) {
      continue;
    }

    if (!entry->mKey.mCallback(aOldElement, aNewElement, entry->mKey.mData)) {
      iter.Remove();
    }
  }
}

void IdentifierMapEntry::AddIdElement(Element* aElement) {
  MOZ_ASSERT(aElement, "Must have element");
  MOZ_ASSERT(!mIdContentList->Contains(nullptr), "Why is null in our list?");

  size_t index = mIdContentList.Insert(*aElement);
  if (index == 0) {
    Element* oldElement = mIdContentList->SafeElementAt(1);
    FireChangeCallbacks(oldElement, aElement);
  }
}

void IdentifierMapEntry::RemoveIdElement(Element* aElement) {
  MOZ_ASSERT(aElement, "Missing element");

  // This should only be called while the document is in an update.
  // Assertions near the call to this method guarantee this.

  // This could fire in OOM situations
  // Only assert this in HTML documents for now as XUL does all sorts of weird
  // crap.
  NS_ASSERTION(!aElement->OwnerDoc()->IsHTMLDocument() ||
                   mIdContentList->Contains(aElement),
               "Removing id entry that doesn't exist");

  // XXXbz should this ever Compact() I guess when all the content is gone
  // we'll just get cleaned up in the natural order of things...
  Element* currentElement = mIdContentList->SafeElementAt(0);
  mIdContentList.RemoveElement(*aElement);
  if (currentElement == aElement) {
    FireChangeCallbacks(currentElement, mIdContentList->SafeElementAt(0));
  }
}

void IdentifierMapEntry::SetImageElement(Element* aElement) {
  Element* oldElement = GetImageIdElement();
  mImageElement = aElement;
  Element* newElement = GetImageIdElement();
  if (oldElement != newElement) {
    FireChangeCallbacks(oldElement, newElement, true);
  }
}

namespace dom {

class SimpleHTMLCollection final : public nsSimpleContentList,
                                   public nsIHTMLCollection {
 public:
  explicit SimpleHTMLCollection(nsINode* aRoot) : nsSimpleContentList(aRoot) {}

  NS_DECL_ISUPPORTS_INHERITED

  virtual nsINode* GetParentObject() override {
    return nsSimpleContentList::GetParentObject();
  }
  virtual uint32_t Length() override { return nsSimpleContentList::Length(); }
  virtual Element* GetElementAt(uint32_t aIndex) override {
    return mElements.SafeElementAt(aIndex)->AsElement();
  }

  virtual Element* GetFirstNamedElement(const nsAString& aName,
                                        bool& aFound) override {
    aFound = false;
    RefPtr<nsAtom> name = NS_Atomize(aName);
    for (uint32_t i = 0; i < mElements.Length(); i++) {
      MOZ_DIAGNOSTIC_ASSERT(mElements[i]);
      Element* element = mElements[i]->AsElement();
      if (element->GetID() == name ||
          (element->HasName() &&
           element->GetParsedAttr(nsGkAtoms::name)->GetAtomValue() == name)) {
        aFound = true;
        return element;
      }
    }
    return nullptr;
  }

  virtual void GetSupportedNames(nsTArray<nsString>& aNames) override {
    AutoTArray<nsAtom*, 8> atoms;
    for (uint32_t i = 0; i < mElements.Length(); i++) {
      MOZ_DIAGNOSTIC_ASSERT(mElements[i]);
      Element* element = mElements[i]->AsElement();

      nsAtom* id = element->GetID();
      MOZ_ASSERT(id != nsGkAtoms::_empty);
      if (id && !atoms.Contains(id)) {
        atoms.AppendElement(id);
      }

      if (element->HasName()) {
        nsAtom* name = element->GetParsedAttr(nsGkAtoms::name)->GetAtomValue();
        MOZ_ASSERT(name && name != nsGkAtoms::_empty);
        if (name && !atoms.Contains(name)) {
          atoms.AppendElement(name);
        }
      }
    }

    nsString* names = aNames.AppendElements(atoms.Length());
    for (uint32_t i = 0; i < atoms.Length(); i++) {
      atoms[i]->ToString(names[i]);
    }
  }

  virtual JSObject* GetWrapperPreserveColorInternal() override {
    return nsWrapperCache::GetWrapperPreserveColor();
  }
  virtual void PreserveWrapperInternal(
      nsISupports* aScriptObjectHolder) override {
    nsWrapperCache::PreserveWrapper(aScriptObjectHolder);
  }
  virtual JSObject* WrapObject(JSContext* aCx,
                               JS::Handle<JSObject*> aGivenProto) override {
    return HTMLCollection_Binding::Wrap(aCx, this, aGivenProto);
  }

  using nsBaseContentList::Item;

 private:
  virtual ~SimpleHTMLCollection() {}
};

NS_IMPL_ISUPPORTS_INHERITED(SimpleHTMLCollection, nsSimpleContentList,
                            nsIHTMLCollection)

}  // namespace dom

void IdentifierMapEntry::AddNameElement(nsINode* aNode, Element* aElement) {
  if (!mNameContentList) {
    mNameContentList = new dom::SimpleHTMLCollection(aNode);
  }

  mNameContentList->AppendElement(aElement);
}

void IdentifierMapEntry::RemoveNameElement(Element* aElement) {
  if (mNameContentList) {
    mNameContentList->RemoveElement(aElement);
  }
}

bool IdentifierMapEntry::HasIdElementExposedAsHTMLDocumentProperty() {
  Element* idElement = GetIdElement();
  return idElement &&
         nsGenericHTMLElement::ShouldExposeIdAsHTMLDocumentProperty(idElement);
}

size_t IdentifierMapEntry::SizeOfExcludingThis(
    MallocSizeOf aMallocSizeOf) const {
  return mKey.mString.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
}

// Helper structs for the content->subdoc map

class SubDocMapEntry : public PLDHashEntryHdr {
 public:
  // Both of these are strong references
  Element* mKey;  // must be first, to look like PLDHashEntryStub
  dom::Document* mSubDocument;
};

class OnloadBlocker final : public nsIRequest {
 public:
  OnloadBlocker() {}

  NS_DECL_ISUPPORTS
  NS_DECL_NSIREQUEST

 private:
  ~OnloadBlocker() {}
};

NS_IMPL_ISUPPORTS(OnloadBlocker, nsIRequest)

NS_IMETHODIMP
OnloadBlocker::GetName(nsACString& aResult) {
  aResult.AssignLiteral("about:document-onload-blocker");
  return NS_OK;
}

NS_IMETHODIMP
OnloadBlocker::IsPending(bool* _retval) {
  *_retval = true;
  return NS_OK;
}

NS_IMETHODIMP
OnloadBlocker::GetStatus(nsresult* status) {
  *status = NS_OK;
  return NS_OK;
}

NS_IMETHODIMP
OnloadBlocker::Cancel(nsresult status) { return NS_OK; }
NS_IMETHODIMP
OnloadBlocker::Suspend(void) { return NS_OK; }
NS_IMETHODIMP
OnloadBlocker::Resume(void) { return NS_OK; }

NS_IMETHODIMP
OnloadBlocker::GetLoadGroup(nsILoadGroup** aLoadGroup) {
  *aLoadGroup = nullptr;
  return NS_OK;
}

NS_IMETHODIMP
OnloadBlocker::SetLoadGroup(nsILoadGroup* aLoadGroup) { return NS_OK; }

NS_IMETHODIMP
OnloadBlocker::GetLoadFlags(nsLoadFlags* aLoadFlags) {
  *aLoadFlags = nsIRequest::LOAD_NORMAL;
  return NS_OK;
}

NS_IMETHODIMP
OnloadBlocker::SetLoadFlags(nsLoadFlags aLoadFlags) { return NS_OK; }

// ==================================================================

namespace dom {

ExternalResourceMap::ExternalResourceMap() : mHaveShutDown(false) {}

Document* ExternalResourceMap::RequestResource(
    nsIURI* aURI, nsIURI* aReferrer, uint32_t aReferrerPolicy,
    nsINode* aRequestingNode, Document* aDisplayDocument,
    ExternalResourceLoad** aPendingLoad) {
  // If we ever start allowing non-same-origin loads here, we might need to do
  // something interesting with aRequestingPrincipal even for the hashtable
  // gets.
  MOZ_ASSERT(aURI, "Must have a URI");
  MOZ_ASSERT(aRequestingNode, "Must have a node");
  *aPendingLoad = nullptr;
  if (mHaveShutDown) {
    return nullptr;
  }

  // First, make sure we strip the ref from aURI.
  nsCOMPtr<nsIURI> clone;
  nsresult rv = NS_GetURIWithoutRef(aURI, getter_AddRefs(clone));
  if (NS_FAILED(rv) || !clone) {
    return nullptr;
  }

  ExternalResource* resource;
  mMap.Get(clone, &resource);
  if (resource) {
    return resource->mDocument;
  }

  RefPtr<PendingLoad>& loadEntry = mPendingLoads.GetOrInsert(clone);
  if (loadEntry) {
    RefPtr<PendingLoad> load(loadEntry);
    load.forget(aPendingLoad);
    return nullptr;
  }

  RefPtr<PendingLoad> load(new PendingLoad(aDisplayDocument));
  loadEntry = load;

  if (NS_FAILED(load->StartLoad(clone, aReferrer, aReferrerPolicy,
                                aRequestingNode))) {
    // Make sure we don't thrash things by trying this load again, since
    // chances are it failed for good reasons (security check, etc).
    AddExternalResource(clone, nullptr, nullptr, aDisplayDocument);
  } else {
    load.forget(aPendingLoad);
  }

  return nullptr;
}

void ExternalResourceMap::EnumerateResources(Document::SubDocEnumFunc aCallback,
                                             void* aData) {
  for (auto iter = mMap.Iter(); !iter.Done(); iter.Next()) {
    ExternalResourceMap::ExternalResource* resource = iter.UserData();
    if (resource->mDocument && !aCallback(resource->mDocument, aData)) {
      break;
    }
  }
}

void ExternalResourceMap::Traverse(
    nsCycleCollectionTraversalCallback* aCallback) const {
  // mPendingLoads will get cleared out as the requests complete, so
  // no need to worry about those here.
  for (auto iter = mMap.ConstIter(); !iter.Done(); iter.Next()) {
    ExternalResourceMap::ExternalResource* resource = iter.UserData();

    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mExternalResourceMap.mMap entry"
                                       "->mDocument");
    aCallback->NoteXPCOMChild(ToSupports(resource->mDocument));

    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mExternalResourceMap.mMap entry"
                                       "->mViewer");
    aCallback->NoteXPCOMChild(resource->mViewer);

    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback,
                                       "mExternalResourceMap.mMap entry"
                                       "->mLoadGroup");
    aCallback->NoteXPCOMChild(resource->mLoadGroup);
  }
}

void ExternalResourceMap::HideViewers() {
  for (auto iter = mMap.Iter(); !iter.Done(); iter.Next()) {
    nsCOMPtr<nsIContentViewer> viewer = iter.UserData()->mViewer;
    if (viewer) {
      viewer->Hide();
    }
  }
}

void ExternalResourceMap::ShowViewers() {
  for (auto iter = mMap.Iter(); !iter.Done(); iter.Next()) {
    nsCOMPtr<nsIContentViewer> viewer = iter.UserData()->mViewer;
    if (viewer) {
      viewer->Show();
    }
  }
}

void TransferZoomLevels(Document* aFromDoc, Document* aToDoc) {
  MOZ_ASSERT(aFromDoc && aToDoc, "transferring zoom levels from/to null doc");

  nsPresContext* fromCtxt = aFromDoc->GetPresContext();
  if (!fromCtxt) return;

  nsPresContext* toCtxt = aToDoc->GetPresContext();
  if (!toCtxt) return;

  toCtxt->SetFullZoom(fromCtxt->GetFullZoom());
  toCtxt->SetTextZoom(fromCtxt->TextZoom());
  toCtxt->SetOverrideDPPX(fromCtxt->GetOverrideDPPX());
}

void TransferShowingState(Document* aFromDoc, Document* aToDoc) {
  MOZ_ASSERT(aFromDoc && aToDoc, "transferring showing state from/to null doc");

  if (aFromDoc->IsShowing()) {
    aToDoc->OnPageShow(true, nullptr);
  }
}

nsresult ExternalResourceMap::AddExternalResource(nsIURI* aURI,
                                                  nsIContentViewer* aViewer,
                                                  nsILoadGroup* aLoadGroup,
                                                  Document* aDisplayDocument) {
  MOZ_ASSERT(aURI, "Unexpected call");
  MOZ_ASSERT((aViewer && aLoadGroup) || (!aViewer && !aLoadGroup),
             "Must have both or neither");

  RefPtr<PendingLoad> load;
  mPendingLoads.Remove(aURI, getter_AddRefs(load));

  nsresult rv = NS_OK;

  nsCOMPtr<Document> doc;
  if (aViewer) {
    doc = aViewer->GetDocument();
    NS_ASSERTION(doc, "Must have a document");

    if (doc->IsXULDocument()) {
      // We don't handle XUL stuff here yet.
      rv = NS_ERROR_NOT_AVAILABLE;
    } else {
      doc->SetDisplayDocument(aDisplayDocument);

      // Make sure that hiding our viewer will tear down its presentation.
      aViewer->SetSticky(false);

      rv = aViewer->Init(nullptr, nsIntRect(0, 0, 0, 0));
      if (NS_SUCCEEDED(rv)) {
        rv = aViewer->Open(nullptr, nullptr);
      }
    }

    if (NS_FAILED(rv)) {
      doc = nullptr;
      aViewer = nullptr;
      aLoadGroup = nullptr;
    }
  }

  ExternalResource* newResource = new ExternalResource();
  mMap.Put(aURI, newResource);

  newResource->mDocument = doc;
  newResource->mViewer = aViewer;
  newResource->mLoadGroup = aLoadGroup;
  if (doc) {
    TransferZoomLevels(aDisplayDocument, doc);
    TransferShowingState(aDisplayDocument, doc);
  }

  const nsTArray<nsCOMPtr<nsIObserver>>& obs = load->Observers();
  for (uint32_t i = 0; i < obs.Length(); ++i) {
    obs[i]->Observe(ToSupports(doc), "external-resource-document-created",
                    nullptr);
  }

  return rv;
}

NS_IMPL_ISUPPORTS(ExternalResourceMap::PendingLoad, nsIStreamListener,
                  nsIRequestObserver)

NS_IMETHODIMP
ExternalResourceMap::PendingLoad::OnStartRequest(nsIRequest* aRequest) {
  ExternalResourceMap& map = mDisplayDocument->ExternalResourceMap();
  if (map.HaveShutDown()) {
    return NS_BINDING_ABORTED;
  }

  nsCOMPtr<nsIContentViewer> viewer;
  nsCOMPtr<nsILoadGroup> loadGroup;
  nsresult rv =
      SetupViewer(aRequest, getter_AddRefs(viewer), getter_AddRefs(loadGroup));

  // Make sure to do this no matter what
  nsresult rv2 =
      map.AddExternalResource(mURI, viewer, loadGroup, mDisplayDocument);
  if (NS_FAILED(rv)) {
    return rv;
  }
  if (NS_FAILED(rv2)) {
    mTargetListener = nullptr;
    return rv2;
  }

  return mTargetListener->OnStartRequest(aRequest);
}

nsresult ExternalResourceMap::PendingLoad::SetupViewer(
    nsIRequest* aRequest, nsIContentViewer** aViewer,
    nsILoadGroup** aLoadGroup) {
  MOZ_ASSERT(!mTargetListener, "Unexpected call to OnStartRequest");
  *aViewer = nullptr;
  *aLoadGroup = nullptr;

  nsCOMPtr<nsIChannel> chan(do_QueryInterface(aRequest));
  NS_ENSURE_TRUE(chan, NS_ERROR_UNEXPECTED);

  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aRequest));
  if (httpChannel) {
    bool requestSucceeded;
    if (NS_FAILED(httpChannel->GetRequestSucceeded(&requestSucceeded)) ||
        !requestSucceeded) {
      // Bail out on this load, since it looks like we have an HTTP error page
      return NS_BINDING_ABORTED;
    }
  }

  nsAutoCString type;
  chan->GetContentType(type);

  nsCOMPtr<nsILoadGroup> loadGroup;
  chan->GetLoadGroup(getter_AddRefs(loadGroup));

  // Give this document its own loadgroup
  nsCOMPtr<nsILoadGroup> newLoadGroup =
      do_CreateInstance(NS_LOADGROUP_CONTRACTID);
  NS_ENSURE_TRUE(newLoadGroup, NS_ERROR_OUT_OF_MEMORY);
  newLoadGroup->SetLoadGroup(loadGroup);

  nsCOMPtr<nsIInterfaceRequestor> callbacks;
  loadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));

  nsCOMPtr<nsIInterfaceRequestor> newCallbacks =
      new LoadgroupCallbacks(callbacks);
  newLoadGroup->SetNotificationCallbacks(newCallbacks);

  // This is some serious hackery cribbed from docshell
  nsCOMPtr<nsICategoryManager> catMan =
      do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
  NS_ENSURE_TRUE(catMan, NS_ERROR_NOT_AVAILABLE);
  nsCString contractId;
  nsresult rv =
      catMan->GetCategoryEntry("Gecko-Content-Viewers", type, contractId);
  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIDocumentLoaderFactory> docLoaderFactory =
      do_GetService(contractId.get());
  NS_ENSURE_TRUE(docLoaderFactory, NS_ERROR_NOT_AVAILABLE);

  nsCOMPtr<nsIContentViewer> viewer;
  nsCOMPtr<nsIStreamListener> listener;
  rv = docLoaderFactory->CreateInstance(
      "external-resource", chan, newLoadGroup, type, nullptr, nullptr,
      getter_AddRefs(listener), getter_AddRefs(viewer));
  NS_ENSURE_SUCCESS(rv, rv);
  NS_ENSURE_TRUE(viewer, NS_ERROR_UNEXPECTED);

  nsCOMPtr<nsIParser> parser = do_QueryInterface(listener);
  if (!parser) {
    /// We don't want to deal with the various fake documents yet
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  // We can't handle HTML and other weird things here yet.
  nsIContentSink* sink = parser->GetContentSink();
  nsCOMPtr<nsIXMLContentSink> xmlSink = do_QueryInterface(sink);
  if (!xmlSink) {
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  listener.swap(mTargetListener);
  viewer.forget(aViewer);
  newLoadGroup.forget(aLoadGroup);
  return NS_OK;
}

NS_IMETHODIMP
ExternalResourceMap::PendingLoad::OnDataAvailable(nsIRequest* aRequest,
                                                  nsIInputStream* aStream,
                                                  uint64_t aOffset,
                                                  uint32_t aCount) {
  // mTargetListener might be null if SetupViewer or AddExternalResource failed.
  NS_ENSURE_TRUE(mTargetListener, NS_ERROR_FAILURE);
  if (mDisplayDocument->ExternalResourceMap().HaveShutDown()) {
    return NS_BINDING_ABORTED;
  }
  return mTargetListener->OnDataAvailable(aRequest, aStream, aOffset, aCount);
}

NS_IMETHODIMP
ExternalResourceMap::PendingLoad::OnStopRequest(nsIRequest* aRequest,
                                                nsresult aStatus) {
  // mTargetListener might be null if SetupViewer or AddExternalResource failed
  if (mTargetListener) {
    nsCOMPtr<nsIStreamListener> listener;
    mTargetListener.swap(listener);
    return listener->OnStopRequest(aRequest, aStatus);
  }

  return NS_OK;
}

nsresult ExternalResourceMap::PendingLoad::StartLoad(nsIURI* aURI,
                                                     nsIURI* aReferrer,
                                                     uint32_t aReferrerPolicy,
                                                     nsINode* aRequestingNode) {
  MOZ_ASSERT(aURI, "Must have a URI");
  MOZ_ASSERT(aRequestingNode, "Must have a node");

  nsCOMPtr<nsILoadGroup> loadGroup =
      aRequestingNode->OwnerDoc()->GetDocumentLoadGroup();

  nsresult rv = NS_OK;
  nsCOMPtr<nsIChannel> channel;
  rv = NS_NewChannel(getter_AddRefs(channel), aURI, aRequestingNode,
                     nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_INHERITS,
                     nsIContentPolicy::TYPE_OTHER,
                     nullptr,  // aPerformanceStorage
                     loadGroup);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(channel));
  if (httpChannel) {
    nsCOMPtr<nsIReferrerInfo> referrerInfo =
        new ReferrerInfo(aReferrer, aReferrerPolicy);
    rv = httpChannel->SetReferrerInfoWithoutClone(referrerInfo);
    Unused << NS_WARN_IF(NS_FAILED(rv));
  }

  mURI = aURI;

  return channel->AsyncOpen(this);
}

NS_IMPL_ISUPPORTS(ExternalResourceMap::LoadgroupCallbacks,
                  nsIInterfaceRequestor)

#define IMPL_SHIM(_i) \
  NS_IMPL_ISUPPORTS(ExternalResourceMap::LoadgroupCallbacks::_i##Shim, _i)

IMPL_SHIM(nsILoadContext)
IMPL_SHIM(nsIProgressEventSink)
IMPL_SHIM(nsIChannelEventSink)
IMPL_SHIM(nsIApplicationCacheContainer)

#undef IMPL_SHIM

#define IID_IS(_i) aIID.Equals(NS_GET_IID(_i))

#define TRY_SHIM(_i)                                 \
  PR_BEGIN_MACRO                                     \
  if (IID_IS(_i)) {                                  \
    nsCOMPtr<_i> real = do_GetInterface(mCallbacks); \
    if (!real) {                                     \
      return NS_NOINTERFACE;                         \
    }                                                \
    nsCOMPtr<_i> shim = new _i##Shim(this, real);    \
    shim.forget(aSink);                              \
    return NS_OK;                                    \
  }                                                  \
  PR_END_MACRO

NS_IMETHODIMP
ExternalResourceMap::LoadgroupCallbacks::GetInterface(const nsIID& aIID,
                                                      void** aSink) {
  if (mCallbacks && (IID_IS(nsIPrompt) || IID_IS(nsIAuthPrompt) ||
                     IID_IS(nsIAuthPrompt2) || IID_IS(nsIBrowserChild))) {
    return mCallbacks->GetInterface(aIID, aSink);
  }

  *aSink = nullptr;

  TRY_SHIM(nsILoadContext);
  TRY_SHIM(nsIProgressEventSink);
  TRY_SHIM(nsIChannelEventSink);
  TRY_SHIM(nsIApplicationCacheContainer);

  return NS_NOINTERFACE;
}

#undef TRY_SHIM
#undef IID_IS

ExternalResourceMap::ExternalResource::~ExternalResource() {
  if (mViewer) {
    mViewer->Close(nullptr);
    mViewer->Destroy();
  }
}

// ==================================================================
// =
// ==================================================================

// If we ever have an nsIDocumentObserver notification for stylesheet title
// changes we should update the list from that instead of overriding
// EnsureFresh.
class DOMStyleSheetSetList final : public DOMStringList {
 public:
  explicit DOMStyleSheetSetList(Document* aDocument);

  void Disconnect() { mDocument = nullptr; }

  virtual void EnsureFresh() override;

 protected:
  Document* mDocument;  // Our document; weak ref.  It'll let us know if it
                        // dies.
};

DOMStyleSheetSetList::DOMStyleSheetSetList(Document* aDocument)
    : mDocument(aDocument) {
  NS_ASSERTION(mDocument, "Must have document!");
}

void DOMStyleSheetSetList::EnsureFresh() {
  MOZ_ASSERT(NS_IsMainThread());

  mNames.Clear();

  if (!mDocument) {
    return;  // Spec says "no exceptions", and we have no style sets if we have
             // no document, for sure
  }

  size_t count = mDocument->SheetCount();
  nsAutoString title;
  for (size_t index = 0; index < count; index++) {
    StyleSheet* sheet = mDocument->SheetAt(index);
    NS_ASSERTION(sheet, "Null sheet in sheet list!");
    sheet->GetTitle(title);
    if (!title.IsEmpty() && !mNames.Contains(title) && !Add(title)) {
      return;
    }
  }
}

// ==================================================================
Document::SelectorCache::SelectorCache(nsIEventTarget* aEventTarget)
    : nsExpirationTracker<SelectorCacheKey, 4>(1000, "Document::SelectorCache",
                                               aEventTarget) {}

Document::SelectorCache::~SelectorCache() { AgeAllGenerations(); }

void Document::SelectorCache::NotifyExpired(SelectorCacheKey* aSelector) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aSelector);

  // There is no guarantee that this method won't be re-entered when selector
  // matching is ongoing because "memory-pressure" could be notified immediately
  // when OOM happens according to the design of nsExpirationTracker.
  // The perfect solution is to delete the |aSelector| and its
  // RawServoSelectorList in mTable asynchronously.
  // We remove these objects synchronously for now because NotifyExpired() will
  // never be triggered by "memory-pressure" which is not implemented yet in
  // the stage 2 of mozalloc_handle_oom().
  // Once these objects are removed asynchronously, we should update the warning
  // added in mozalloc_handle_oom() as well.
  RemoveObject(aSelector);
  mTable.Remove(aSelector->mKey);
  delete aSelector;
}

Document::FrameRequest::FrameRequest(FrameRequestCallback& aCallback,
                                     int32_t aHandle)
    : mCallback(&aCallback), mHandle(aHandle) {}

// ==================================================================
// =
// ==================================================================
Document::Document(const char* aContentType)
    : nsINode(nullptr),
      DocumentOrShadowRoot(*this),
      mReferrerPolicySet(false),
      mReferrerPolicy(mozilla::net::RP_Unset),
      mBlockAllMixedContent(false),
      mBlockAllMixedContentPreloads(false),
      mUpgradeInsecureRequests(false),
      mUpgradeInsecurePreloads(false),
      mCharacterSet(WINDOWS_1252_ENCODING),
      mCharacterSetSource(0),
      mParentDocument(nullptr),
      mCachedRootElement(nullptr),
      mNodeInfoManager(nullptr),
#ifdef DEBUG
      mStyledLinksCleared(false),
#endif
      mBidiEnabled(false),
      mMayNeedFontPrefsUpdate(true),
      mMathMLEnabled(false),
      mIsInitialDocumentInWindow(false),
      mIgnoreDocGroupMismatches(false),
      mLoadedAsData(false),
      mLoadedAsInteractiveData(false),
      mMayStartLayout(true),
      mHaveFiredTitleChange(false),
      mIsShowing(false),
      mVisible(true),
      mRemovedFromDocShell(false),
      // mAllowDNSPrefetch starts true, so that we can always reliably && it
      // with various values that might disable it.  Since we never prefetch
      // unless we get a window, and in that case the docshell value will get
      // &&-ed in, this is safe.
      mAllowDNSPrefetch(true),
      mIsStaticDocument(false),
      mCreatingStaticClone(false),
      mInUnlinkOrDeletion(false),
      mHasHadScriptHandlingObject(false),
      mIsBeingUsedAsImage(false),
      mDocURISchemeIsChrome(false),
      mInChromeDocShell(false),
      mIsSyntheticDocument(false),
      mHasLinksToUpdateRunnable(false),
      mFlushingPendingLinkUpdates(false),
      mMayHaveDOMMutationObservers(false),
      mMayHaveAnimationObservers(false),
      mHasMixedActiveContentLoaded(false),
      mHasMixedActiveContentBlocked(false),
      mHasMixedDisplayContentLoaded(false),
      mHasMixedDisplayContentBlocked(false),
      mHasMixedContentObjectSubrequest(false),
      mHasCSP(false),
      mHasUnsafeEvalCSP(false),
      mHasUnsafeInlineCSP(false),
      mBFCacheDisallowed(false),
      mHasHadDefaultView(false),
      mStyleSheetChangeEventsEnabled(false),
      mIsSrcdocDocument(false),
      mHasDisplayDocument(false),
      mFontFaceSetDirty(true),
      mDidFireDOMContentLoaded(true),
      mHasScrollLinkedEffect(false),
      mFrameRequestCallbacksScheduled(false),
      mIsTopLevelContentDocument(false),
      mIsContentDocument(false),
      mDidCallBeginLoad(false),
      mAllowPaymentRequest(false),
      mEncodingMenuDisabled(false),
      mIsSVGGlyphsDocument(false),
      mInDestructor(false),
      mIsGoingAway(false),
      mInXBLUpdate(false),
      mNeedsReleaseAfterStackRefCntRelease(false),
      mStyleSetFilled(false),
      mQuirkSheetAdded(false),
      mContentEditableSheetAdded(false),
      mDesignModeSheetAdded(false),
      mSSApplicableStateNotificationPending(false),
      mMayHaveTitleElement(false),
      mDOMLoadingSet(false),
      mDOMInteractiveSet(false),
      mDOMCompleteSet(false),
      mAutoFocusFired(false),
      mScrolledToRefAlready(false),
      mChangeScrollPosWhenScrollingToRef(false),
      mHasWarnedAboutBoxObjects(false),
      mDelayFrameLoaderInitialization(false),
      mSynchronousDOMContentLoaded(false),
      mMaybeServiceWorkerControlled(false),
      mAllowZoom(false),
      mValidScaleFloat(false),
      mValidMaxScale(false),
      mScaleStrEmpty(false),
      mWidthStrEmpty(false),
      mParserAborted(false),
      mReportedUseCounters(false),
      mHasReportedShadowDOMUsage(false),
      mDocTreeHadAudibleMedia(false),
      mDocTreeHadPlayRevoked(false),
      mHasDelayedRefreshEvent(false),
      mLoadEventFiring(false),
      mSkipLoadEventAfterClose(false),
      mDisableCookieAccess(false),
      mPendingFullscreenRequests(0),
      mXMLDeclarationBits(0),
      mOnloadBlockCount(0),
      mAsyncOnloadBlockCount(0),
      mCompatMode(eCompatibility_FullStandards),
      mReadyState(ReadyState::READYSTATE_UNINITIALIZED),
      mAncestorIsLoading(false),
#ifdef MOZILLA_INTERNAL_API
      mVisibilityState(dom::VisibilityState::Hidden),
#else
      mDummy(0),
#endif
      mType(eUnknown),
      mDefaultElementType(0),
      mAllowXULXBL(eTriUnset),
      mBidiOptions(IBMBIDI_DEFAULT_BIDI_OPTIONS),
      mSandboxFlags(0),
      mPartID(0),
      mMarkedCCGeneration(0),
      mPresShell(nullptr),
      mSubtreeModifiedDepth(0),
      mPreloadPictureDepth(0),
      mEventsSuppressed(0),
      mIgnoreDestructiveWritesCounter(0),
      mFrameRequestCallbackCounter(0),
      mStaticCloneCount(0),
      mWindow(nullptr),
      mBFCacheEntry(nullptr),
      mInSyncOperationCount(0),
      mBlockDOMContentLoaded(0),
      mUseCounters(0),
      mChildDocumentUseCounters(0),
      mNotifiedPageForUseCounter(0),
      mUserHasInteracted(false),
      mHasUserInteractionTimerScheduled(false),
      mStackRefCnt(0),
      mUpdateNestLevel(0),
      mViewportType(Unknown),
      mSubDocuments(nullptr),
      mHeaderData(nullptr),
      mFlashClassification(FlashClassification::Unknown),
      mScrollAnchorAdjustmentLength(0),
      mScrollAnchorAdjustmentCount(0),
      mBoxObjectTable(nullptr),
      mCurrentOrientationAngle(0),
      mCurrentOrientationType(OrientationType::Portrait_primary),
      mServoRestyleRootDirtyBits(0),
      mThrowOnDynamicMarkupInsertionCounter(0),
      mIgnoreOpensDuringUnloadCounter(0),
      mDocLWTheme(Doc_Theme_Uninitialized),
      mSavedResolution(1.0f),
      mPendingInitialTranslation(false),
      mGeneration(0),
      mCachedTabSizeGeneration(0),
      mInRDMPane(false) {
  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p created", this));

  SetIsInDocument();
  SetIsConnected(true);

  if (StaticPrefs::layout_css_use_counters_enabled()) {
    mStyleUseCounters = Servo_UseCounters_Create().Consume();
  }

  SetContentTypeInternal(nsDependentCString(aContentType));

  // Start out mLastStyleSheetSet as null, per spec
  SetDOMStringToNull(mLastStyleSheetSet);

  // void state used to differentiate an empty source from an unselected source
  mPreloadPictureFoundSource.SetIsVoid(true);

  RecomputeLanguageFromCharset();
}

void Document::ClearAllBoxObjects() {
  if (mBoxObjectTable) {
    for (auto iter = mBoxObjectTable->Iter(); !iter.Done(); iter.Next()) {
      nsPIBoxObject* boxObject = iter.UserData();
      if (boxObject) {
        boxObject->Clear();
      }
    }
    delete mBoxObjectTable;
    mBoxObjectTable = nullptr;
  }
}

bool Document::IsAboutPage() const {
  nsCOMPtr<nsIPrincipal> principal = NodePrincipal();
  nsCOMPtr<nsIURI> uri;
  principal->GetURI(getter_AddRefs(uri));
  bool isAboutScheme = true;
  if (uri) {
    uri->SchemeIs("about", &isAboutScheme);
  }
  return isAboutScheme;
}

void Document::ConstructUbiNode(void* storage) {
  JS::ubi::Concrete<Document>::construct(storage, this);
}

Document::~Document() {
  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p destroyed", this));
  MOZ_ASSERT(!IsTopLevelContentDocument() || !IsResourceDoc(),
             "Can't be top-level and a resource doc at the same time");

  NS_ASSERTION(!mIsShowing, "Destroying a currently-showing document");

  if (IsTopLevelContentDocument()) {
    // don't report for about: pages
    if (!IsAboutPage()) {
      // Record the page load
      uint32_t pageLoaded = 1;
      Accumulate(Telemetry::MIXED_CONTENT_UNBLOCK_COUNTER, pageLoaded);
      // Record the mixed content status of the docshell in Telemetry
      enum {
        NO_MIXED_CONTENT = 0,  // There is no Mixed Content on the page
        MIXED_DISPLAY_CONTENT =
            1,  // The page attempted to load Mixed Display Content
        MIXED_ACTIVE_CONTENT =
            2,  // The page attempted to load Mixed Active Content
        MIXED_DISPLAY_AND_ACTIVE_CONTENT =
            3  // The page attempted to load Mixed Display & Mixed Active
               // Content
      };

      bool mixedActiveLoaded = GetHasMixedActiveContentLoaded();
      bool mixedActiveBlocked = GetHasMixedActiveContentBlocked();

      bool mixedDisplayLoaded = GetHasMixedDisplayContentLoaded();
      bool mixedDisplayBlocked = GetHasMixedDisplayContentBlocked();

      bool hasMixedDisplay = (mixedDisplayBlocked || mixedDisplayLoaded);
      bool hasMixedActive = (mixedActiveBlocked || mixedActiveLoaded);

      uint32_t mixedContentLevel = NO_MIXED_CONTENT;
      if (hasMixedDisplay && hasMixedActive) {
        mixedContentLevel = MIXED_DISPLAY_AND_ACTIVE_CONTENT;
      } else if (hasMixedActive) {
        mixedContentLevel = MIXED_ACTIVE_CONTENT;
      } else if (hasMixedDisplay) {
        mixedContentLevel = MIXED_DISPLAY_CONTENT;
      }
      Accumulate(Telemetry::MIXED_CONTENT_PAGE_LOAD, mixedContentLevel);

      // record mixed object subrequest telemetry
      if (mHasMixedContentObjectSubrequest) {
        /* mixed object subrequest loaded on page*/
        Accumulate(Telemetry::MIXED_CONTENT_OBJECT_SUBREQUEST, 1);
      } else {
        /* no mixed object subrequests loaded on page*/
        Accumulate(Telemetry::MIXED_CONTENT_OBJECT_SUBREQUEST, 0);
      }

      // record CSP telemetry on this document
      if (mHasCSP) {
        Accumulate(Telemetry::CSP_DOCUMENTS_COUNT, 1);
      }
      if (mHasUnsafeInlineCSP) {
        Accumulate(Telemetry::CSP_UNSAFE_INLINE_DOCUMENTS_COUNT, 1);
      }
      if (mHasUnsafeEvalCSP) {
        Accumulate(Telemetry::CSP_UNSAFE_EVAL_DOCUMENTS_COUNT, 1);
      }

      if (MOZ_UNLIKELY(mMathMLEnabled)) {
        ScalarAdd(Telemetry::ScalarID::MATHML_DOC_COUNT, 1);
      }

      ScalarAdd(Telemetry::ScalarID::MEDIA_PAGE_COUNT, 1);
      if (mDocTreeHadAudibleMedia) {
        ScalarAdd(Telemetry::ScalarID::MEDIA_PAGE_HAD_MEDIA_COUNT, 1);
      }
      if (mDocTreeHadPlayRevoked) {
        ScalarAdd(Telemetry::ScalarID::MEDIA_PAGE_HAD_PLAY_REVOKED_COUNT, 1);
      }

      if (IsHTMLDocument()) {
        switch (GetCompatibilityMode()) {
          case eCompatibility_FullStandards:
            Telemetry::AccumulateCategorical(
                Telemetry::LABELS_QUIRKS_MODE::FullStandards);
            break;
          case eCompatibility_AlmostStandards:
            Telemetry::AccumulateCategorical(
                Telemetry::LABELS_QUIRKS_MODE::AlmostStandards);
            break;
          case eCompatibility_NavQuirks:
            Telemetry::AccumulateCategorical(
                Telemetry::LABELS_QUIRKS_MODE::NavQuirks);
            break;
          default:
            MOZ_ASSERT_UNREACHABLE("Unknown quirks mode");
            break;
        }
      }
    }
  }

  ReportUseCounters();

  mInDestructor = true;
  mInUnlinkOrDeletion = true;

  mozilla::DropJSObjects(this);

  // Clear mObservers to keep it in sync with the mutationobserver list
  mObservers.Clear();

  mIntersectionObservers.Clear();

  if (mStyleSheetSetList) {
    mStyleSheetSetList->Disconnect();
  }

  if (mAnimationController) {
    mAnimationController->Disconnect();
  }

  MOZ_ASSERT(mTimelines.isEmpty());

  mParentDocument = nullptr;

  // Kill the subdocument map, doing this will release its strong
  // references, if any.
  delete mSubDocuments;
  mSubDocuments = nullptr;

  // Destroy link map now so we don't waste time removing
  // links one by one
  DestroyElementMaps();

  nsAutoScriptBlocker scriptBlocker;

  // Invalidate cached array of child nodes
  InvalidateChildNodes();

  // We should not have child nodes when destructor is called,
  // since child nodes keep their owner document alive.
  MOZ_ASSERT(!HasChildren());

  mCachedRootElement = nullptr;

  for (auto& sheets : mAdditionalSheets) {
    for (StyleSheet* sheet : sheets) {
      sheet->ClearAssociatedDocumentOrShadowRoot();
    }
  }

  if (mAttrStyleSheet) {
    mAttrStyleSheet->SetOwningDocument(nullptr);
  }

  if (mListenerManager) {
    mListenerManager->Disconnect();
    UnsetFlags(NODE_HAS_LISTENERMANAGER);
  }

  if (mScriptLoader) {
    mScriptLoader->DropDocumentReference();
  }

  if (mCSSLoader) {
    // Could be null here if Init() failed or if we have been unlinked.
    mCSSLoader->DropDocumentReference();
  }

  if (mStyleImageLoader) {
    mStyleImageLoader->DropDocumentReference();
  }

  if (mXULBroadcastManager) {
    mXULBroadcastManager->DropDocumentReference();
  }

  if (mXULPersist) {
    mXULPersist->DropDocumentReference();
  }

  delete mHeaderData;

  ClearAllBoxObjects();

  mPendingTitleChangeEvent.Revoke();

  mPlugins.Clear();

  MOZ_ASSERT(mDOMMediaQueryLists.isEmpty(),
             "must not have media query lists left");

  if (mNodeInfoManager) {
    mNodeInfoManager->DropDocumentReference();
  }

  if (mDocGroup) {
    mDocGroup->RemoveDocument(this);
  }

  UnlinkOriginalDocumentIfStatic();
}

NS_INTERFACE_TABLE_HEAD(Document)
  NS_WRAPPERCACHE_INTERFACE_TABLE_ENTRY
  NS_INTERFACE_TABLE_BEGIN
    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(Document, nsISupports, nsINode)
    NS_INTERFACE_TABLE_ENTRY(Document, nsINode)
    NS_INTERFACE_TABLE_ENTRY(Document, Document)
    NS_INTERFACE_TABLE_ENTRY(Document, nsIScriptObjectPrincipal)
    NS_INTERFACE_TABLE_ENTRY(Document, mozilla::dom::EventTarget)
    NS_INTERFACE_TABLE_ENTRY(Document, nsISupportsWeakReference)
    NS_INTERFACE_TABLE_ENTRY(Document, nsIRadioGroupContainer)
    NS_INTERFACE_TABLE_ENTRY(Document, nsIMutationObserver)
    NS_INTERFACE_TABLE_ENTRY(Document, nsIApplicationCacheContainer)
  NS_INTERFACE_TABLE_END
  NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(Document)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(Document)
NS_IMETHODIMP_(MozExternalRefCountType)
Document::Release() {
  MOZ_ASSERT(0 != mRefCnt, "dup release");
  NS_ASSERT_OWNINGTHREAD(Document);
  nsISupports* base = NS_CYCLE_COLLECTION_CLASSNAME(Document)::Upcast(this);
  bool shouldDelete = false;
  nsrefcnt count = mRefCnt.decr(base, &shouldDelete);
  NS_LOG_RELEASE(this, count, "Document");
  if (count == 0) {
    if (mStackRefCnt && !mNeedsReleaseAfterStackRefCntRelease) {
      mNeedsReleaseAfterStackRefCntRelease = true;
      NS_ADDREF_THIS();
      return mRefCnt.get();
    }
    mRefCnt.incr(base);
    nsNodeUtils::LastRelease(this);
    mRefCnt.decr(base);
    if (shouldDelete) {
      mRefCnt.stabilizeForDeletion();
      DeleteCycleCollectable();
    }
  }
  return count;
}

NS_IMETHODIMP_(void)
Document::DeleteCycleCollectable() { delete this; }

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(Document)
  if (Element::CanSkip(tmp, aRemovingAllowed)) {
    EventListenerManager* elm = tmp->GetExistingListenerManager();
    if (elm) {
      elm->MarkForCC();
    }
    return true;
  }
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(Document)
  return Element::CanSkipInCC(tmp);
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(Document)
  return Element::CanSkipThis(tmp);
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(Document)
  if (MOZ_UNLIKELY(cb.WantDebugInfo())) {
    char name[512];
    nsAutoCString loadedAsData;
    if (tmp->IsLoadedAsData()) {
      loadedAsData.AssignLiteral("data");
    } else {
      loadedAsData.AssignLiteral("normal");
    }
    uint32_t nsid = tmp->GetDefaultNamespaceID();
    nsAutoCString uri;
    if (tmp->mDocumentURI) uri = tmp->mDocumentURI->GetSpecOrDefault();
    static const char* kNSURIs[] = {"([none])", "(xmlns)", "(xml)", "(xhtml)",
                                    "(XLink)",  "(XSLT)",  "(XBL)", "(MathML)",
                                    "(RDF)",    "(XUL)"};
    if (nsid < ArrayLength(kNSURIs)) {
      SprintfLiteral(name, "Document %s %s %s", loadedAsData.get(),
                     kNSURIs[nsid], uri.get());
    } else {
      SprintfLiteral(name, "Document %s %s", loadedAsData.get(), uri.get());
    }
    cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name);
  } else {
    NS_IMPL_CYCLE_COLLECTION_DESCRIBE(Document, tmp->mRefCnt.get())
  }

  if (!nsINode::Traverse(tmp, cb)) {
    return NS_SUCCESS_INTERRUPTED_TRAVERSE;
  }

  if (tmp->mMaybeEndOutermostXBLUpdateRunner) {
    // The cached runnable keeps a reference to the document object..
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(
        cb, "mMaybeEndOutermostXBLUpdateRunner.mObj");
    cb.NoteXPCOMChild(ToSupports(tmp));
  }

  tmp->mExternalResourceMap.Traverse(&cb);

  // Traverse all Document pointer members.
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSecurityInfo)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDisplayDocument)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFontFaceSet)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mReadyForIdle)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocumentL10n)

  // Traverse all Document nsCOMPtrs.
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParser)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mScriptGlobalObject)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mListenerManager)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheetSetList)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mScriptLoader)

  DocumentOrShadowRoot::Traverse(tmp, cb);

  // The boxobject for an element will only exist as long as it's in the
  // document, so we'll traverse the table here instead of from the element.
  if (tmp->mBoxObjectTable) {
    for (auto iter = tmp->mBoxObjectTable->Iter(); !iter.Done(); iter.Next()) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mBoxObjectTable entry");
      cb.NoteXPCOMChild(iter.UserData());
    }
  }

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChannel)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLayoutHistoryState)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOnloadBlocker)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDOMImplementation)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mImageMaps)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOrientationPendingPromise)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOriginalDocument)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCachedEncoder)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStateObjectCached)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocumentTimeline)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPendingAnimationTracker)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTemplateContentsOwner)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChildrenCollection)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mImages);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mEmbeds);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLinks);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mForms);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mScripts);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mApplets);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAnchors);
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAnonymousContents)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCommandDispatcher)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFeaturePolicy)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSuppressedEventListener)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPrototypeDocument)

  // Traverse all our nsCOMArrays.
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPreloadingImages)

  for (uint32_t i = 0; i < tmp->mFrameRequestCallbacks.Length(); ++i) {
    NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mFrameRequestCallbacks[i]");
    cb.NoteXPCOMChild(tmp->mFrameRequestCallbacks[i].mCallback);
  }

  // Traverse animation components
  if (tmp->mAnimationController) {
    tmp->mAnimationController->Traverse(&cb);
  }

  if (tmp->mSubDocuments) {
    for (auto iter = tmp->mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
      auto entry = static_cast<SubDocMapEntry*>(iter.Get());

      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mSubDocuments entry->mKey");
      cb.NoteXPCOMChild(entry->mKey);
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb,
                                         "mSubDocuments entry->mSubDocument");
      cb.NoteXPCOMChild(ToSupports(entry->mSubDocument));
    }
  }

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCSSLoader)

  // We own only the items in mDOMMediaQueryLists that have listeners;
  // this reference is managed by their AddListener and RemoveListener
  // methods.
  for (MediaQueryList* mql = tmp->mDOMMediaQueryLists.getFirst(); mql;
       mql = static_cast<LinkedListElement<MediaQueryList>*>(mql)->getNext()) {
    if (mql->HasListeners() &&
        NS_SUCCEEDED(mql->CheckCurrentGlobalCorrectness())) {
      NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mDOMMediaQueryLists item");
      cb.NoteXPCOMChild(mql);
    }
  }

  if (tmp->mResizeObserverController) {
    tmp->mResizeObserverController->Traverse(cb);
  }
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_CLASS(Document)

NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(Document)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Document)
  tmp->mInUnlinkOrDeletion = true;

  // Clear out our external resources
  tmp->mExternalResourceMap.Shutdown();

  nsAutoScriptBlocker scriptBlocker;

  nsINode::Unlink(tmp);

  while (tmp->HasChildren()) {
    // Hold a strong ref to the node when we remove it, because we may be
    // the last reference to it.
    // If this code changes, change the corresponding code in Document's
    // unlink impl and ContentUnbinder::UnbindSubtree.
    nsCOMPtr<nsIContent> child = tmp->GetLastChild();
    tmp->DisconnectChild(child);
    child->UnbindFromTree();
  }

  tmp->UnlinkOriginalDocumentIfStatic();

  tmp->mCachedRootElement = nullptr;  // Avoid a dangling pointer
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDisplayDocument)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mMaybeEndOutermostXBLUpdateRunner)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDOMImplementation)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mImageMaps)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCachedEncoder)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocumentTimeline)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPendingAnimationTracker)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mTemplateContentsOwner)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mChildrenCollection)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mImages);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mEmbeds);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mLinks);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mForms);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mScripts);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mApplets);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mAnchors);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOrientationPendingPromise)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mFontFaceSet)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mReadyForIdle);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCommandDispatcher)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocumentL10n);
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mFeaturePolicy)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSuppressedEventListener)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPrototypeDocument)

  tmp->mParentDocument = nullptr;

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPreloadingImages)

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mIntersectionObservers)

  tmp->ClearAllBoxObjects();

  if (tmp->mListenerManager) {
    tmp->mListenerManager->Disconnect();
    tmp->UnsetFlags(NODE_HAS_LISTENERMANAGER);
    tmp->mListenerManager = nullptr;
  }

  if (tmp->mStyleSheetSetList) {
    tmp->mStyleSheetSetList->Disconnect();
    tmp->mStyleSheetSetList = nullptr;
  }

  delete tmp->mSubDocuments;
  tmp->mSubDocuments = nullptr;

  tmp->mFrameRequestCallbacks.Clear();
  MOZ_RELEASE_ASSERT(!tmp->mFrameRequestCallbacksScheduled,
                     "How did we get here without our presshell going away "
                     "first?");

  DocumentOrShadowRoot::Unlink(tmp);

  // Document has a pretty complex destructor, so we're going to
  // assume that *most* cycles you actually want to break somewhere
  // else, and not unlink an awful lot here.

  tmp->mExpandoAndGeneration.OwnerUnlinked();

  if (tmp->mAnimationController) {
    tmp->mAnimationController->Unlink();
  }

  tmp->mPendingTitleChangeEvent.Revoke();

  if (tmp->mCSSLoader) {
    tmp->mCSSLoader->DropDocumentReference();
    NS_IMPL_CYCLE_COLLECTION_UNLINK(mCSSLoader)
  }

  // We own only the items in mDOMMediaQueryLists that have listeners;
  // this reference is managed by their AddListener and RemoveListener
  // methods.
  for (MediaQueryList* mql = tmp->mDOMMediaQueryLists.getFirst(); mql;) {
    MediaQueryList* next =
        static_cast<LinkedListElement<MediaQueryList>*>(mql)->getNext();
    mql->Disconnect();
    mql = next;
  }

  tmp->mInUnlinkOrDeletion = false;

  if (tmp->mResizeObserverController) {
    tmp->mResizeObserverController->Unlink();
  }
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

nsresult Document::Init() {
  if (mCSSLoader || mStyleImageLoader || mNodeInfoManager || mScriptLoader) {
    return NS_ERROR_ALREADY_INITIALIZED;
  }

  // Force initialization.
  nsINode::nsSlots* slots = Slots();

  // Prepend self as mutation-observer whether we need it or not (some
  // subclasses currently do, other don't). This is because the code in
  // nsNodeUtils always notifies the first observer first, expecting the
  // first observer to be the document.
  slots->mMutationObservers.PrependElementUnlessExists(
      static_cast<nsIMutationObserver*>(this));

  mOnloadBlocker = new OnloadBlocker();
  mCSSLoader = new mozilla::css::Loader(this);
  // Assume we're not quirky, until we know otherwise
  mCSSLoader->SetCompatibilityMode(eCompatibility_FullStandards);

  mStyleImageLoader = new mozilla::css::ImageLoader(this);

  mNodeInfoManager = new nsNodeInfoManager();
  nsresult rv = mNodeInfoManager->Init(this);
  NS_ENSURE_SUCCESS(rv, rv);

  // mNodeInfo keeps NodeInfoManager alive!
  mNodeInfo = mNodeInfoManager->GetDocumentNodeInfo();
  NS_ENSURE_TRUE(mNodeInfo, NS_ERROR_OUT_OF_MEMORY);
  MOZ_ASSERT(mNodeInfo->NodeType() == DOCUMENT_NODE,
             "Bad NodeType in aNodeInfo");

  NS_ASSERTION(OwnerDoc() == this, "Our nodeinfo is busted!");

  // If after creation the owner js global is not set for a document
  // we use the default compartment for this document, instead of creating
  // wrapper in some random compartment when the document is exposed to js
  // via some events.
  nsCOMPtr<nsIGlobalObject> global =
      xpc::NativeGlobal(xpc::PrivilegedJunkScope());
  NS_ENSURE_TRUE(global, NS_ERROR_FAILURE);
  mScopeObject = do_GetWeakReference(global);
  MOZ_ASSERT(mScopeObject);

  mScriptLoader = new dom::ScriptLoader(this);

  // we need to create a policy here so getting the policy within
  // ::Policy() can *always* return a non null policy
  mFeaturePolicy = new FeaturePolicy(this);
  mFeaturePolicy->SetDefaultOrigin(NodePrincipal());

  mStyleSet = MakeUnique<ServoStyleSet>(*this);

  mozilla::HoldJSObjects(this);

  return NS_OK;
}

void Document::DeleteAllProperties() { PropertyTable().DeleteAllProperties(); }

void Document::DeleteAllPropertiesFor(nsINode* aNode) {
  PropertyTable().DeleteAllPropertiesFor(aNode);
}

bool Document::IsVisibleConsideringAncestors() const {
  const Document* parent = this;
  do {
    if (!parent->IsVisible()) {
      return false;
    }
  } while ((parent = parent->GetParentDocument()));

  return true;
}

void Document::Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup) {
  nsCOMPtr<nsIURI> uri;
  nsCOMPtr<nsIPrincipal> principal;
  nsCOMPtr<nsIPrincipal> storagePrincipal;
  if (aChannel) {
    // Note: this code is duplicated in XULDocument::StartDocumentLoad and
    // nsScriptSecurityManager::GetChannelResultPrincipals.
    // Note: this should match nsDocShell::OnLoadingSite
    NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));

    nsIScriptSecurityManager* securityManager =
        nsContentUtils::GetSecurityManager();
    if (securityManager) {
      securityManager->GetChannelResultPrincipals(
          aChannel, getter_AddRefs(principal),
          getter_AddRefs(storagePrincipal));
    }
  }

  bool equal = principal->Equals(storagePrincipal);

  principal = MaybeDowngradePrincipal(principal);
  if (equal) {
    storagePrincipal = principal;
  } else {
    storagePrincipal = MaybeDowngradePrincipal(storagePrincipal);
  }

  ResetToURI(uri, aLoadGroup, principal, storagePrincipal);

  // Note that, since mTiming does not change during a reset, the
  // navigationStart time remains unchanged and therefore any future new
  // timeline will have the same global clock time as the old one.
  mDocumentTimeline = nullptr;

  nsCOMPtr<nsIPropertyBag2> bag = do_QueryInterface(aChannel);
  if (bag) {
    nsCOMPtr<nsIURI> baseURI;
    bag->GetPropertyAsInterface(NS_LITERAL_STRING("baseURI"),
                                NS_GET_IID(nsIURI), getter_AddRefs(baseURI));
    if (baseURI) {
      mDocumentBaseURI = baseURI;
      mChromeXHRDocBaseURI = nullptr;
    }
  }

  mChannel = aChannel;
}

/**
 * Determine whether the principal is allowed access to the localization system.
 * We don't want the web to ever see this but all our UI including in content
 * pages should pass this test.
 */
bool PrincipalAllowsL10n(nsIPrincipal* principal) {
  // The system principal is always allowed.
  if (nsContentUtils::IsSystemPrincipal(principal)) {
    return true;
  }

  nsCOMPtr<nsIURI> uri;
  nsresult rv = principal->GetURI(getter_AddRefs(uri));
  NS_ENSURE_SUCCESS(rv, false);

  bool hasFlags;

  // Allow access to uris that cannot be loaded by web content.
  rv = NS_URIChainHasFlags(uri, nsIProtocolHandler::URI_DANGEROUS_TO_LOAD,
                           &hasFlags);
  NS_ENSURE_SUCCESS(rv, false);
  if (hasFlags) {
    return true;
  }

  // UI resources also get access.
  rv = NS_URIChainHasFlags(uri, nsIProtocolHandler::URI_IS_UI_RESOURCE,
                           &hasFlags);
  NS_ENSURE_SUCCESS(rv, false);
  return hasFlags;
}

void Document::DisconnectNodeTree() {
  // Delete references to sub-documents and kill the subdocument map,
  // if any. This is not strictly needed, but makes the node tree
  // teardown a bit faster.
  delete mSubDocuments;
  mSubDocuments = nullptr;

  // Destroy link map now so we don't waste time removing
  // links one by one
  DestroyElementMaps();

  bool oldVal = mInUnlinkOrDeletion;
  mInUnlinkOrDeletion = true;
  {  // Scope for update
    MOZ_AUTO_DOC_UPDATE(this, true);

    // Invalidate cached array of child nodes
    InvalidateChildNodes();

    while (HasChildren()) {
      nsCOMPtr<nsIContent> content = GetLastChild();
      nsIContent* previousSibling = content->GetPreviousSibling();
      DisconnectChild(content);
      if (content == mCachedRootElement) {
        // Immediately clear mCachedRootElement, now that it's been removed
        // from mChildren, so that GetRootElement() will stop returning this
        // now-stale value.
        mCachedRootElement = nullptr;
      }
      nsNodeUtils::ContentRemoved(this, content, previousSibling);
      content->UnbindFromTree();
    }
    MOZ_ASSERT(!mCachedRootElement,
               "After removing all children, there should be no root elem");
  }
  mInUnlinkOrDeletion = oldVal;
}

void Document::ResetToURI(nsIURI* aURI, nsILoadGroup* aLoadGroup,
                          nsIPrincipal* aPrincipal,
                          nsIPrincipal* aStoragePrincipal) {
  MOZ_ASSERT(aURI, "Null URI passed to ResetToURI");
  MOZ_ASSERT(!!aPrincipal == !!aStoragePrincipal);

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug,
          ("DOCUMENT %p ResetToURI %s", this, aURI->GetSpecOrDefault().get()));

  mSecurityInfo = nullptr;

  nsCOMPtr<nsILoadGroup> group = do_QueryReferent(mDocumentLoadGroup);
  if (!aLoadGroup || group != aLoadGroup) {
    mDocumentLoadGroup = nullptr;
  }

  DisconnectNodeTree();

  // Reset our stylesheets
  ResetStylesheetsToURI(aURI);

  // Release the listener manager
  if (mListenerManager) {
    mListenerManager->Disconnect();
    mListenerManager = nullptr;
  }

  // Release the stylesheets list.
  mDOMStyleSheets = nullptr;

  // Release our principal after tearing down the document, rather than before.
  // This ensures that, during teardown, the document and the dying window
  // (which already nulled out its document pointer and cached the principal)
  // have matching principals.
  SetPrincipals(nullptr, nullptr);

  // Clear the original URI so SetDocumentURI sets it.
  mOriginalURI = nullptr;

  SetDocumentURI(aURI);
  mChromeXHRDocURI = nullptr;
  // If mDocumentBaseURI is null, Document::GetBaseURI() returns
  // mDocumentURI.
  mDocumentBaseURI = nullptr;
  mChromeXHRDocBaseURI = nullptr;

  if (aLoadGroup) {
    mDocumentLoadGroup = do_GetWeakReference(aLoadGroup);
    // there was an assertion here that aLoadGroup was not null.  This
    // is no longer valid: nsDocShell::SetDocument does not create a
    // load group, and it works just fine

    // XXXbz what does "just fine" mean exactly?  And given that there
    // is no nsDocShell::SetDocument, what is this talking about?

    if (IsContentDocument()) {
      // Inform the associated request context about this load start so
      // any of its internal load progress flags gets reset.
      nsCOMPtr<nsIRequestContextService> rcsvc =
          mozilla::net::RequestContextService::GetOrCreate();
      if (rcsvc) {
        nsCOMPtr<nsIRequestContext> rc;
        rcsvc->GetRequestContextFromLoadGroup(aLoadGroup, getter_AddRefs(rc));
        if (rc) {
          rc->BeginLoad();
        }
      }
    }
  }

  mLastModified.Truncate();
  // XXXbz I guess we're assuming that the caller will either pass in
  // a channel with a useful type or call SetContentType?
  SetContentTypeInternal(EmptyCString());
  mContentLanguage.Truncate();
  mBaseTarget.Truncate();
  mReferrer.Truncate();

  mXMLDeclarationBits = 0;

  // Now get our new principal
  if (aPrincipal) {
    SetPrincipals(aPrincipal, aStoragePrincipal);
  } else {
    nsIScriptSecurityManager* securityManager =
        nsContentUtils::GetSecurityManager();
    if (securityManager) {
      nsCOMPtr<nsILoadContext> loadContext(mDocumentContainer);

      if (!loadContext && aLoadGroup) {
        nsCOMPtr<nsIInterfaceRequestor> cbs;
        aLoadGroup->GetNotificationCallbacks(getter_AddRefs(cbs));
        loadContext = do_GetInterface(cbs);
      }

      MOZ_ASSERT(loadContext,
                 "must have a load context or pass in an explicit principal");

      nsCOMPtr<nsIPrincipal> principal;
      nsresult rv = securityManager->GetLoadContextCodebasePrincipal(
          mDocumentURI, loadContext, getter_AddRefs(principal));
      if (NS_SUCCEEDED(rv)) {
        SetPrincipals(principal, principal);
      }
    }
  }

  if (mFontFaceSet) {
    mFontFaceSet->RefreshStandardFontLoadPrincipal();
  }

  // Refresh the principal on the realm.
  if (nsPIDOMWindowInner* win = GetInnerWindow()) {
    nsGlobalWindowInner::Cast(win)->RefreshRealmPrincipal();
  }
}

already_AddRefed<nsIPrincipal> Document::MaybeDowngradePrincipal(
    nsIPrincipal* aPrincipal) {
  if (!aPrincipal) {
    return nullptr;
  }

  // We can't load a document with an expanded principal. If we're given one,
  // automatically downgrade it to the last principal it subsumes (which is the
  // extension principal, in the case of extension content scripts).
  auto* basePrin = BasePrincipal::Cast(aPrincipal);
  if (basePrin->Is<ExpandedPrincipal>()) {
    MOZ_DIAGNOSTIC_ASSERT(false,
                          "Should never try to create a document with "
                          "an expanded principal");

    auto* expanded = basePrin->As<ExpandedPrincipal>();
    return do_AddRef(expanded->AllowList().LastElement());
  }

  if (nsContentUtils::IsSystemPrincipal(aPrincipal)) {
    // We basically want the parent document here, but because this is very
    // early in the load, GetParentDocument() returns null, so we use the
    // docshell hierarchy to get this information instead.
    if (mDocumentContainer) {
      nsCOMPtr<nsIDocShellTreeItem> parentDocShellItem;
      mDocumentContainer->GetParent(getter_AddRefs(parentDocShellItem));
      nsCOMPtr<nsIDocShell> parentDocShell =
          do_QueryInterface(parentDocShellItem);
      if (parentDocShell) {
        nsCOMPtr<Document> parentDoc;
        parentDoc = parentDocShell->GetDocument();
        if (!parentDoc ||
            !nsContentUtils::IsSystemPrincipal(parentDoc->NodePrincipal())) {
          nsCOMPtr<nsIPrincipal> nullPrincipal =
              do_CreateInstance("@mozilla.org/nullprincipal;1");
          return nullPrincipal.forget();
        }
      }
    }
  }
  nsCOMPtr<nsIPrincipal> principal(aPrincipal);
  return principal.forget();
}

size_t Document::FindDocStyleSheetInsertionPoint(const StyleSheet& aSheet) {
  nsStyleSheetService* sheetService = nsStyleSheetService::GetInstance();

  // lowest index first
  int32_t newDocIndex = IndexOfSheet(aSheet);

  size_t count = mStyleSet->SheetCount(StyleOrigin::Author);
  size_t index = 0;
  for (; index < count; index++) {
    auto* sheet = mStyleSet->SheetAt(StyleOrigin::Author, index);
    MOZ_ASSERT(sheet);
    int32_t sheetDocIndex = IndexOfSheet(*sheet);
    if (sheetDocIndex > newDocIndex) break;

    // If the sheet is not owned by the document it can be an author
    // sheet registered at nsStyleSheetService or an additional author
    // sheet on the document, which means the new
    // doc sheet should end up before it.
    if (sheetDocIndex < 0) {
      if (sheetService) {
        auto& authorSheets = *sheetService->AuthorStyleSheets();
        if (authorSheets.IndexOf(sheet) != authorSheets.NoIndex) {
          break;
        }
      }
      if (sheet == GetFirstAdditionalAuthorSheet()) {
        break;
      }
    }
  }

  return index;
}

void Document::RemoveDocStyleSheetsFromStyleSets() {
  MOZ_ASSERT(mStyleSetFilled);
  // The stylesheets should forget us
  for (StyleSheet* sheet : Reversed(mStyleSheets)) {
    sheet->ClearAssociatedDocumentOrShadowRoot();
    if (sheet->IsApplicable()) {
      mStyleSet->RemoveDocStyleSheet(sheet);
    }
    // XXX Tell observers?
  }
}

void Document::RemoveStyleSheetsFromStyleSets(
    const nsTArray<RefPtr<StyleSheet>>& aSheets, StyleOrigin aType) {
  // The stylesheets should forget us
  for (StyleSheet* sheet : Reversed(aSheets)) {
    sheet->ClearAssociatedDocumentOrShadowRoot();
    if (mStyleSetFilled && sheet->IsApplicable()) {
      mStyleSet->RemoveStyleSheet(aType, sheet);
    }
    // XXX Tell observers?
  }
}

void Document::ResetStylesheetsToURI(nsIURI* aURI) {
  MOZ_ASSERT(aURI);

  if (mStyleSetFilled) {
    // Skip removing style sheets from the style set if we know we haven't
    // filled the style set.  (This allows us to avoid calling
    // GetStyleBackendType() too early.)
    RemoveDocStyleSheetsFromStyleSets();
    RemoveStyleSheetsFromStyleSets(mAdditionalSheets[eAgentSheet],
                                   StyleOrigin::UserAgent);
    RemoveStyleSheetsFromStyleSets(mAdditionalSheets[eUserSheet],
                                   StyleOrigin::User);
    RemoveStyleSheetsFromStyleSets(mAdditionalSheets[eAuthorSheet],
                                   StyleOrigin::Author);

    if (nsStyleSheetService* sheetService =
            nsStyleSheetService::GetInstance()) {
      RemoveStyleSheetsFromStyleSets(*sheetService->AuthorStyleSheets(),
                                     StyleOrigin::Author);
    }
  }

  // Release all the sheets
  mStyleSheets.Clear();
  for (auto& sheets : mAdditionalSheets) {
    sheets.Clear();
  }

  // NOTE:  We don't release the catalog sheets.  It doesn't really matter
  // now, but it could in the future -- in which case not releasing them
  // is probably the right thing to do.

  // Now reset our inline style and attribute sheets.
  if (mAttrStyleSheet) {
    mAttrStyleSheet->Reset();
    mAttrStyleSheet->SetOwningDocument(this);
  } else {
    mAttrStyleSheet = new nsHTMLStyleSheet(this);
  }

  if (!mStyleAttrStyleSheet) {
    mStyleAttrStyleSheet = new nsHTMLCSSStyleSheet();
  }

  if (mStyleSetFilled) {
    FillStyleSetDocumentSheets();

    if (mStyleSet->StyleSheetsHaveChanged()) {
      ApplicableStylesChanged();
    }
  }
}

static void AppendSheetsToStyleSet(ServoStyleSet* aStyleSet,
                                   const nsTArray<RefPtr<StyleSheet>>& aSheets,
                                   StyleOrigin aOrigin) {
  for (StyleSheet* sheet : Reversed(aSheets)) {
    aStyleSet->AppendStyleSheet(aOrigin, sheet);
  }
}

void Document::FillStyleSetUserAndUASheets() {
  // Make sure this does the same thing as PresShell::Add{User,Agent}Sheet wrt
  // ordering.

  // The document will fill in the document sheets when we create the presshell
  auto cache = nsLayoutStylesheetCache::Singleton();

  nsStyleSheetService* sheetService = nsStyleSheetService::GetInstance();
  MOZ_ASSERT(sheetService,
             "should never be creating a StyleSet after the style sheet "
             "service has gone");

  for (StyleSheet* sheet : *sheetService->UserStyleSheets()) {
    mStyleSet->AppendStyleSheet(StyleOrigin::User, sheet);
  }

  StyleSheet* sheet = IsInChromeDocShell() ? cache->GetUserChromeSheet()
                                           : cache->GetUserContentSheet();
  if (sheet) {
    mStyleSet->AppendStyleSheet(StyleOrigin::User, sheet);
  }

  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->UASheet());

  if (MOZ_LIKELY(NodeInfoManager()->MathMLEnabled())) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->MathMLSheet());
  }

  if (MOZ_LIKELY(NodeInfoManager()->SVGEnabled())) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->SVGSheet());
  }

  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->HTMLSheet());

  if (nsLayoutUtils::ShouldUseNoFramesSheet(this)) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->NoFramesSheet());
  }

  if (nsLayoutUtils::ShouldUseNoScriptSheet(this)) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->NoScriptSheet());
  }

  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent,
                              cache->CounterStylesSheet());

  // Load the minimal XUL rules for scrollbars and a few other XUL things
  // that non-XUL (typically HTML) documents commonly use.
  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->MinimalXULSheet());

  // Only load the full XUL sheet if we'll need it.
  if (LoadsFullXULStyleSheetUpFront()) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->XULSheet());
  }

  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->FormsSheet());
  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->ScrollbarsSheet());
  mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent,
                              cache->PluginProblemSheet());

  for (StyleSheet* sheet : *sheetService->AgentStyleSheets()) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, sheet);
  }

  MOZ_ASSERT(!mQuirkSheetAdded);
  if (NeedsQuirksSheet()) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, cache->QuirkSheet());
    mQuirkSheetAdded = true;
  }
}

void Document::FillStyleSet() {
  MOZ_ASSERT(!mStyleSetFilled);
  FillStyleSetUserAndUASheets();
  FillStyleSetDocumentSheets();
  mStyleSetFilled = true;
}

void Document::RemoveContentEditableStyleSheets() {
  MOZ_ASSERT(IsHTMLOrXHTML());

  auto* cache = nsLayoutStylesheetCache::Singleton();
  bool changed = false;
  if (mDesignModeSheetAdded) {
    mStyleSet->RemoveStyleSheet(StyleOrigin::UserAgent,
                                cache->DesignModeSheet());
    mDesignModeSheetAdded = false;
    changed = true;
  }
  if (mContentEditableSheetAdded) {
    mStyleSet->RemoveStyleSheet(StyleOrigin::UserAgent,
                                cache->ContentEditableSheet());
    mContentEditableSheetAdded = false;
    changed = true;
  }
  if (changed) {
    MOZ_ASSERT(mStyleSetFilled);
    ApplicableStylesChanged();
  }
}

void Document::AddContentEditableStyleSheetsToStyleSet(bool aDesignMode) {
  MOZ_ASSERT(IsHTMLOrXHTML());
  MOZ_DIAGNOSTIC_ASSERT(mStyleSetFilled,
                        "Caller should ensure we're being rendered");

  auto* cache = nsLayoutStylesheetCache::Singleton();
  bool changed = false;
  if (!mContentEditableSheetAdded) {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent,
                                cache->ContentEditableSheet());
    mContentEditableSheetAdded = true;
    changed = true;
  }
  if (mDesignModeSheetAdded != aDesignMode) {
    if (mDesignModeSheetAdded) {
      mStyleSet->RemoveStyleSheet(StyleOrigin::UserAgent,
                                  cache->DesignModeSheet());
    } else {
      mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent,
                                  cache->DesignModeSheet());
    }
    mDesignModeSheetAdded = !mDesignModeSheetAdded;
    changed = true;
  }
  if (changed) {
    ApplicableStylesChanged();
  }
}

void Document::FillStyleSetDocumentSheets() {
  MOZ_ASSERT(mStyleSet->SheetCount(StyleOrigin::Author) == 0,
             "Style set already has document sheets?");

  for (StyleSheet* sheet : Reversed(mStyleSheets)) {
    if (sheet->IsApplicable()) {
      mStyleSet->AddDocStyleSheet(sheet);
    }
  }

  nsStyleSheetService* sheetService = nsStyleSheetService::GetInstance();
  for (StyleSheet* sheet : *sheetService->AuthorStyleSheets()) {
    mStyleSet->AppendStyleSheet(StyleOrigin::Author, sheet);
  }

  AppendSheetsToStyleSet(mStyleSet.get(), mAdditionalSheets[eAgentSheet],
                         StyleOrigin::UserAgent);
  AppendSheetsToStyleSet(mStyleSet.get(), mAdditionalSheets[eUserSheet],
                         StyleOrigin::User);
  AppendSheetsToStyleSet(mStyleSet.get(), mAdditionalSheets[eAuthorSheet],
                         StyleOrigin::Author);
}

void Document::CompatibilityModeChanged() {
  MOZ_ASSERT(IsHTMLOrXHTML());
  CSSLoader()->SetCompatibilityMode(mCompatMode);
  mStyleSet->CompatibilityModeChanged();
  if (PresShell* presShell = GetPresShell()) {
    // Selectors may have become case-sensitive / case-insensitive, the stylist
    // has already performed the relevant invalidation.
    presShell->EnsureStyleFlush();
  }
  if (!mStyleSetFilled) {
    MOZ_ASSERT(!mQuirkSheetAdded);
    return;
  }
  if (mQuirkSheetAdded == NeedsQuirksSheet()) {
    return;
  }
  auto cache = nsLayoutStylesheetCache::Singleton();
  StyleSheet* sheet = cache->QuirkSheet();
  if (mQuirkSheetAdded) {
    mStyleSet->RemoveStyleSheet(StyleOrigin::UserAgent, sheet);
  } else {
    mStyleSet->AppendStyleSheet(StyleOrigin::UserAgent, sheet);
  }
  mQuirkSheetAdded = !mQuirkSheetAdded;
  ApplicableStylesChanged();
}

static void WarnIfSandboxIneffective(nsIDocShell* aDocShell,
                                     uint32_t aSandboxFlags,
                                     nsIChannel* aChannel) {
  // If the document is sandboxed (via the HTML5 iframe sandbox
  // attribute) and both the allow-scripts and allow-same-origin
  // keywords are supplied, the sandboxed document can call into its
  // parent document and remove its sandboxing entirely - we print a
  // warning to the web console in this case.
  if (aSandboxFlags & SANDBOXED_NAVIGATION &&
      !(aSandboxFlags & SANDBOXED_SCRIPTS) &&
      !(aSandboxFlags & SANDBOXED_ORIGIN)) {
    nsCOMPtr<nsIDocShellTreeItem> parentAsItem;
    aDocShell->GetSameTypeParent(getter_AddRefs(parentAsItem));
    nsCOMPtr<nsIDocShell> parentDocShell = do_QueryInterface(parentAsItem);
    if (!parentDocShell) {
      return;
    }

    // Don't warn if our parent is not the top-level document.
    nsCOMPtr<nsIDocShellTreeItem> grandParentAsItem;
    parentDocShell->GetSameTypeParent(getter_AddRefs(grandParentAsItem));
    if (grandParentAsItem) {
      return;
    }

    nsCOMPtr<nsIChannel> parentChannel;
    parentDocShell->GetCurrentDocumentChannel(getter_AddRefs(parentChannel));
    if (!parentChannel) {
      return;
    }
    nsresult rv = nsContentUtils::CheckSameOrigin(aChannel, parentChannel);
    if (NS_FAILED(rv)) {
      return;
    }

    nsCOMPtr<Document> parentDocument = parentDocShell->GetDocument();
    nsCOMPtr<nsIURI> iframeUri;
    parentChannel->GetURI(getter_AddRefs(iframeUri));
    nsContentUtils::ReportToConsole(
        nsIScriptError::warningFlag, NS_LITERAL_CSTRING("Iframe Sandbox"),
        parentDocument, nsContentUtils::eSECURITY_PROPERTIES,
        "BothAllowScriptsAndSameOriginPresent", nullptr, 0, iframeUri);
  }
}

bool Document::IsSynthesized() {
  nsCOMPtr<nsILoadInfo> loadInfo = mChannel ? mChannel->LoadInfo() : nullptr;
  return loadInfo && loadInfo->GetServiceWorkerTaintingSynthesized();
}

// static
bool Document::IsCallerChromeOrAddon(JSContext* aCx, JSObject* aObject) {
  nsIPrincipal* principal = nsContentUtils::SubjectPrincipal(aCx);
  return principal && (nsContentUtils::IsSystemPrincipal(principal) ||
                       principal->GetIsAddonOrExpandedAddonPrincipal());
}

nsresult Document::StartDocumentLoad(const char* aCommand, nsIChannel* aChannel,
                                     nsILoadGroup* aLoadGroup,
                                     nsISupports* aContainer,
                                     nsIStreamListener** aDocListener,
                                     bool aReset, nsIContentSink* aSink) {
  if (MOZ_LOG_TEST(gDocumentLeakPRLog, LogLevel::Debug)) {
    nsCOMPtr<nsIURI> uri;
    aChannel->GetURI(getter_AddRefs(uri));
    MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug,
            ("DOCUMENT %p StartDocumentLoad %s", this,
             uri ? uri->GetSpecOrDefault().get() : ""));
  }

  MOZ_ASSERT(GetReadyStateEnum() == Document::READYSTATE_UNINITIALIZED,
             "Bad readyState");
  SetReadyStateInternal(READYSTATE_LOADING);

  if (nsCRT::strcmp(kLoadAsData, aCommand) == 0) {
    mLoadedAsData = true;
    // We need to disable script & style loading in this case.
    // We leave them disabled even in EndLoad(), and let anyone
    // who puts the document on display to worry about enabling.

    // Do not load/process scripts when loading as data
    ScriptLoader()->SetEnabled(false);

    // styles
    CSSLoader()->SetEnabled(
        false);  // Do not load/process styles when loading as data
  } else if (nsCRT::strcmp("external-resource", aCommand) == 0) {
    // Allow CSS, but not scripts
    ScriptLoader()->SetEnabled(false);
  }

  mMayStartLayout = false;
  MOZ_ASSERT(!mReadyForIdle,
             "We should never hit DOMContentLoaded before this point");

  if (aReset) {
    Reset(aChannel, aLoadGroup);
  }

  nsAutoCString contentType;
  nsCOMPtr<nsIPropertyBag2> bag = do_QueryInterface(aChannel);
  if ((bag && NS_SUCCEEDED(bag->GetPropertyAsACString(
                  NS_LITERAL_STRING("contentType"), contentType))) ||
      NS_SUCCEEDED(aChannel->GetContentType(contentType))) {
    // XXX this is only necessary for viewsource:
    nsACString::const_iterator start, end, semicolon;
    contentType.BeginReading(start);
    contentType.EndReading(end);
    semicolon = start;
    FindCharInReadable(';', semicolon, end);
    SetContentTypeInternal(Substring(start, semicolon));
  }

  RetrieveRelevantHeaders(aChannel);

  mChannel = aChannel;
  nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(mChannel);
  if (inStrmChan) {
    bool isSrcdocChannel;
    inStrmChan->GetIsSrcdocChannel(&isSrcdocChannel);
    if (isSrcdocChannel) {
      mIsSrcdocDocument = true;
    }
  }

  if (mChannel) {
    nsLoadFlags loadFlags;
    mChannel->GetLoadFlags(&loadFlags);
    bool isDocument = false;
    mChannel->GetIsDocument(&isDocument);
    if (loadFlags & nsIRequest::LOAD_DOCUMENT_NEEDS_COOKIE && isDocument &&
        IsSynthesized() && XRE_IsContentProcess()) {
      ContentChild::UpdateCookieStatus(mChannel);
    }
  }

  // If this document is being loaded by a docshell, copy its sandbox flags
  // to the document, and store the fullscreen enabled flag. These are
  // immutable after being set here.
  nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(aContainer);

  // If this is an error page, don't inherit sandbox flags from docshell
  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();
  if (docShell && !loadInfo->GetLoadErrorPage()) {
    nsresult rv = docShell->GetSandboxFlags(&mSandboxFlags);
    NS_ENSURE_SUCCESS(rv, rv);
    WarnIfSandboxIneffective(docShell, mSandboxFlags, GetChannel());
  }

  // The CSP directive upgrade-insecure-requests not only applies to the
  // toplevel document, but also to nested documents. Let's propagate that
  // flag from the parent to the nested document.
  nsCOMPtr<nsIDocShellTreeItem> treeItem = this->GetDocShell();
  if (treeItem) {
    nsCOMPtr<nsIDocShellTreeItem> sameTypeParent;
    treeItem->GetSameTypeParent(getter_AddRefs(sameTypeParent));
    if (sameTypeParent) {
      Document* doc = sameTypeParent->GetDocument();
      mBlockAllMixedContent = doc->GetBlockAllMixedContent(false);
      // if the parent document makes use of block-all-mixed-content
      // then subdocument preloads should always be blocked.
      mBlockAllMixedContentPreloads =
          mBlockAllMixedContent || doc->GetBlockAllMixedContent(true);

      mUpgradeInsecureRequests = doc->GetUpgradeInsecureRequests(false);
      // if the parent document makes use of upgrade-insecure-requests
      // then subdocument preloads should always be upgraded.
      mUpgradeInsecurePreloads =
          mUpgradeInsecureRequests || doc->GetUpgradeInsecureRequests(true);
    }
  }

  nsresult rv = InitCSP(aChannel);
  NS_ENSURE_SUCCESS(rv, rv);

  // Initialize FeaturePolicy
  rv = InitFeaturePolicy(aChannel);
  NS_ENSURE_SUCCESS(rv, rv);

  // XFO needs to be checked after CSP because it is ignored if
  // the CSP defines frame-ancestors.
  if (!FramingChecker::CheckFrameOptions(aChannel, docShell, NodePrincipal())) {
    MOZ_LOG(gCspPRLog, LogLevel::Debug,
            ("XFO doesn't like frame's ancestry, not loading."));
    // stop!  ERROR page!
    aChannel->Cancel(NS_ERROR_CSP_FRAME_ANCESTOR_VIOLATION);
  }

  // Let's take the CookieSettings from the loadInfo or from the parent
  // document.
  if (loadInfo) {
    rv = loadInfo->GetCookieSettings(getter_AddRefs(mCookieSettings));
    NS_ENSURE_SUCCESS(rv, rv);
  } else {
    nsCOMPtr<Document> parentDocument = GetParentDocument();
    if (parentDocument) {
      mCookieSettings = parentDocument->CookieSettings();
    }
  }

  return NS_OK;
}

void Document::SendToConsole(nsCOMArray<nsISecurityConsoleMessage>& aMessages) {
  for (uint32_t i = 0; i < aMessages.Length(); ++i) {
    nsAutoString messageTag;
    aMessages[i]->GetTag(messageTag);

    nsAutoString category;
    aMessages[i]->GetCategory(category);

    nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                    NS_ConvertUTF16toUTF8(category), this,
                                    nsContentUtils::eSECURITY_PROPERTIES,
                                    NS_ConvertUTF16toUTF8(messageTag).get());
  }
}

void Document::ApplySettingsFromCSP(bool aSpeculative) {
  nsresult rv = NS_OK;
  if (!aSpeculative) {
    // 1) apply settings from regular CSP
    nsCOMPtr<nsIContentSecurityPolicy> csp;
    rv = NodePrincipal()->GetCsp(getter_AddRefs(csp));
    NS_ENSURE_SUCCESS_VOID(rv);
    if (csp) {
      // Set up 'block-all-mixed-content' if not already inherited
      // from the parent context or set by any other CSP.
      if (!mBlockAllMixedContent) {
        rv = csp->GetBlockAllMixedContent(&mBlockAllMixedContent);
        NS_ENSURE_SUCCESS_VOID(rv);
      }
      if (!mBlockAllMixedContentPreloads) {
        mBlockAllMixedContentPreloads = mBlockAllMixedContent;
      }

      // Set up 'upgrade-insecure-requests' if not already inherited
      // from the parent context or set by any other CSP.
      if (!mUpgradeInsecureRequests) {
        rv = csp->GetUpgradeInsecureRequests(&mUpgradeInsecureRequests);
        NS_ENSURE_SUCCESS_VOID(rv);
      }
      if (!mUpgradeInsecurePreloads) {
        mUpgradeInsecurePreloads = mUpgradeInsecureRequests;
      }
    }
    return;
  }

  // 2) apply settings from speculative csp
  nsCOMPtr<nsIContentSecurityPolicy> preloadCsp;
  rv = NodePrincipal()->GetPreloadCsp(getter_AddRefs(preloadCsp));
  NS_ENSURE_SUCCESS_VOID(rv);
  if (preloadCsp) {
    if (!mBlockAllMixedContentPreloads) {
      rv = preloadCsp->GetBlockAllMixedContent(&mBlockAllMixedContentPreloads);
      NS_ENSURE_SUCCESS_VOID(rv);
    }
    if (!mUpgradeInsecurePreloads) {
      rv = preloadCsp->GetUpgradeInsecureRequests(&mUpgradeInsecurePreloads);
      NS_ENSURE_SUCCESS_VOID(rv);
    }
  }
}

nsresult Document::InitCSP(nsIChannel* aChannel) {
  MOZ_ASSERT(!mScriptGlobalObject,
             "CSP must be initialized before mScriptGlobalObject is set!");
  if (!StaticPrefs::security_csp_enable()) {
    MOZ_LOG(gCspPRLog, LogLevel::Debug,
            ("CSP is disabled, skipping CSP init for document %p", this));
    return NS_OK;
  }

  // If this is a data document - no need to set CSP.
  if (mLoadedAsData) {
    return NS_OK;
  }

  nsAutoCString tCspHeaderValue, tCspROHeaderValue;

  nsCOMPtr<nsIHttpChannel> httpChannel;
  nsresult rv = GetHttpChannelHelper(aChannel, getter_AddRefs(httpChannel));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (httpChannel) {
    Unused << httpChannel->GetResponseHeader(
        NS_LITERAL_CSTRING("content-security-policy"), tCspHeaderValue);

    Unused << httpChannel->GetResponseHeader(
        NS_LITERAL_CSTRING("content-security-policy-report-only"),
        tCspROHeaderValue);
  }
  NS_ConvertASCIItoUTF16 cspHeaderValue(tCspHeaderValue);
  NS_ConvertASCIItoUTF16 cspROHeaderValue(tCspROHeaderValue);

  // Check if this is a document from a WebExtension.
  nsCOMPtr<nsIPrincipal> principal = NodePrincipal();
  auto addonPolicy = BasePrincipal::Cast(principal)->AddonPolicy();

  // Unless the NodePrincipal is a SystemPrincipal, which currently can not
  // hold a CSP, we always call EnsureCSP() on the Principal. We do this
  // so that a Meta CSP does not have to create a new CSP object. This is
  // important because history entries hold a reference to the CSP object,
  // which then gets dynamically updated in case a meta CSP is present.
  // Note that after Bug 965637 we can remove that carve out, because the
  // CSP will hang off the Client/Document and not the Principal anymore.
  if (principal->IsSystemPrincipal()) {
    return NS_OK;
  }
  nsCOMPtr<nsIContentSecurityPolicy> csp;
  rv = principal->EnsureCSP(this, getter_AddRefs(csp));
  NS_ENSURE_SUCCESS(rv, rv);

  // If there's no CSP to apply, go ahead and return early
  if (!addonPolicy && cspHeaderValue.IsEmpty() && cspROHeaderValue.IsEmpty()) {
    if (MOZ_LOG_TEST(gCspPRLog, LogLevel::Debug)) {
      nsCOMPtr<nsIURI> chanURI;
      aChannel->GetURI(getter_AddRefs(chanURI));
      nsAutoCString aspec;
      chanURI->GetAsciiSpec(aspec);
      MOZ_LOG(gCspPRLog, LogLevel::Debug,
              ("no CSP for document, %s", aspec.get()));
    }

    return NS_OK;
  }

  MOZ_LOG(gCspPRLog, LogLevel::Debug,
          ("Document is an add-on or CSP header specified %p", this));

  // ----- if the doc is an addon, apply its CSP.
  if (addonPolicy) {
    nsAutoString addonCSP;
    Unused << ExtensionPolicyService::GetSingleton().GetBaseCSP(addonCSP);
    csp->AppendPolicy(addonCSP, false, false);

    csp->AppendPolicy(addonPolicy->ContentSecurityPolicy(), false, false);
  }

  // ----- if there's a full-strength CSP header, apply it.
  if (!cspHeaderValue.IsEmpty()) {
    rv = CSP_AppendCSPFromHeader(csp, cspHeaderValue, false);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // ----- if there's a report-only CSP header, apply it.
  if (!cspROHeaderValue.IsEmpty()) {
    rv = CSP_AppendCSPFromHeader(csp, cspROHeaderValue, true);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  // ----- Enforce sandbox policy if supplied in CSP header
  // The document may already have some sandbox flags set (e.g. if the document
  // is an iframe with the sandbox attribute set). If we have a CSP sandbox
  // directive, intersect the CSP sandbox flags with the existing flags. This
  // corresponds to the _least_ permissive policy.
  uint32_t cspSandboxFlags = SANDBOXED_NONE;
  rv = csp->GetCSPSandboxFlags(&cspSandboxFlags);
  NS_ENSURE_SUCCESS(rv, rv);

  // Probably the iframe sandbox attribute already caused the creation of a
  // new NullPrincipal. Only create a new NullPrincipal if CSP requires so
  // and no one has been created yet.
  bool needNewNullPrincipal = (cspSandboxFlags & SANDBOXED_ORIGIN) &&
                              !(mSandboxFlags & SANDBOXED_ORIGIN);

  mSandboxFlags |= cspSandboxFlags;

  if (needNewNullPrincipal) {
    principal = NullPrincipal::CreateWithInheritedAttributes(principal);
    principal->SetCsp(csp);
    SetPrincipals(principal, principal);
  }

  // ----- Enforce frame-ancestor policy on any applied policies
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
  if (docShell) {
    bool safeAncestry = false;

    // PermitsAncestry sends violation reports when necessary
    rv = csp->PermitsAncestry(docShell, &safeAncestry);

    if (NS_FAILED(rv) || !safeAncestry) {
      MOZ_LOG(gCspPRLog, LogLevel::Debug,
              ("CSP doesn't like frame's ancestry, not loading."));
      // stop!  ERROR page!
      aChannel->Cancel(NS_ERROR_CSP_FRAME_ANCESTOR_VIOLATION);
    }
  }
  ApplySettingsFromCSP(false);
  return NS_OK;
}

nsresult Document::InitFeaturePolicy(nsIChannel* aChannel) {
  MOZ_ASSERT(mFeaturePolicy, "we should only call init once");

  mFeaturePolicy->ResetDeclaredPolicy();

  if (!StaticPrefs::dom_security_featurePolicy_enabled()) {
    return NS_OK;
  }

  mFeaturePolicy->SetDefaultOrigin(NodePrincipal());

  RefPtr<FeaturePolicy> parentPolicy = nullptr;
  if (mDocumentContainer) {
    nsPIDOMWindowOuter* containerWindow = mDocumentContainer->GetWindow();
    if (containerWindow) {
      nsCOMPtr<nsINode> node = containerWindow->GetFrameElementInternal();
      HTMLIFrameElement* iframe = HTMLIFrameElement::FromNodeOrNull(node);
      if (iframe) {
        parentPolicy = iframe->Policy();
      }
    }
  }

  if (parentPolicy) {
    // Let's inherit the policy from the parent HTMLIFrameElement if it exists.
    mFeaturePolicy->InheritPolicy(parentPolicy);
  }

  // We don't want to parse the http Feature-Policy header if this pref is off.
  if (!StaticPrefs::dom_security_featurePolicy_header_enabled()) {
    return NS_OK;
  }

  nsCOMPtr<nsIHttpChannel> httpChannel;
  nsresult rv = GetHttpChannelHelper(aChannel, getter_AddRefs(httpChannel));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (!httpChannel) {
    return NS_OK;
  }

  // query the policy from the header
  nsAutoCString value;
  rv = httpChannel->GetResponseHeader(NS_LITERAL_CSTRING("Feature-Policy"),
                                      value);
  if (NS_SUCCEEDED(rv)) {
    mFeaturePolicy->SetDeclaredPolicy(this, NS_ConvertUTF8toUTF16(value),
                                      NodePrincipal(), nullptr);
  }

  return NS_OK;
}

void Document::StopDocumentLoad() {
  if (mParser) {
    mParserAborted = true;
    mParser->Terminate();
  }
}

void Document::SetDocumentURI(nsIURI* aURI) {
  nsCOMPtr<nsIURI> oldBase = GetDocBaseURI();
  mDocumentURI = aURI;
  nsIURI* newBase = GetDocBaseURI();

  mDocURISchemeIsChrome = aURI && IsChromeURI(aURI);

  bool equalBases = false;
  // Changing just the ref of a URI does not change how relative URIs would
  // resolve wrt to it, so we can treat the bases as equal as long as they're
  // equal ignoring the ref.
  if (oldBase && newBase) {
    oldBase->EqualsExceptRef(newBase, &equalBases);
  } else {
    equalBases = !oldBase && !newBase;
  }

  // If this is the first time we're setting the document's URI, set the
  // document's original URI.
  if (!mOriginalURI) mOriginalURI = mDocumentURI;

  // If changing the document's URI changed the base URI of the document, we
  // need to refresh the hrefs of all the links on the page.
  if (!equalBases) {
    RefreshLinkHrefs();
  }

  // Recalculate our base domain
  mBaseDomain.Truncate();
  ThirdPartyUtil* thirdPartyUtil = ThirdPartyUtil::GetInstance();
  if (thirdPartyUtil) {
    Unused << thirdPartyUtil->GetBaseDomain(mDocumentURI, mBaseDomain);
  }

  // Tell our WindowGlobalParent that the document's URI has been changed.
  nsPIDOMWindowInner* inner = GetInnerWindow();
  WindowGlobalChild* wgc = inner ? inner->GetWindowGlobalChild() : nullptr;
  if (wgc) {
    Unused << wgc->SendUpdateDocumentURI(mDocumentURI);
  }
}

static void GetFormattedTimeString(PRTime aTime,
                                   nsAString& aFormattedTimeString) {
  PRExplodedTime prtime;
  PR_ExplodeTime(aTime, PR_LocalTimeParameters, &prtime);
  // "MM/DD/YYYY hh:mm:ss"
  char formatedTime[24];
  if (SprintfLiteral(formatedTime, "%02d/%02d/%04d %02d:%02d:%02d",
                     prtime.tm_month + 1, prtime.tm_mday, int(prtime.tm_year),
                     prtime.tm_hour, prtime.tm_min, prtime.tm_sec)) {
    CopyASCIItoUTF16(nsDependentCString(formatedTime), aFormattedTimeString);
  } else {
    // If we for whatever reason failed to find the last modified time
    // (or even the current time), fall back to what NS4.x returned.
    aFormattedTimeString.AssignLiteral(u"01/01/1970 00:00:00");
  }
}

void Document::GetLastModified(nsAString& aLastModified) const {
  if (!mLastModified.IsEmpty()) {
    aLastModified.Assign(mLastModified);
  } else {
    GetFormattedTimeString(PR_Now(), aLastModified);
  }
}

static void IncrementExpandoGeneration(Document& aDoc) {
  ++aDoc.mExpandoAndGeneration.generation;
}

void Document::AddToNameTable(Element* aElement, nsAtom* aName) {
  MOZ_ASSERT(
      nsGenericHTMLElement::ShouldExposeNameAsHTMLDocumentProperty(aElement),
      "Only put elements that need to be exposed as document['name'] in "
      "the named table.");

  IdentifierMapEntry* entry = mIdentifierMap.PutEntry(aName);

  // Null for out-of-memory
  if (entry) {
    if (!entry->HasNameElement() &&
        !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
      IncrementExpandoGeneration(*this);
    }
    entry->AddNameElement(this, aElement);
  }
}

void Document::RemoveFromNameTable(Element* aElement, nsAtom* aName) {
  // Speed up document teardown
  if (mIdentifierMap.Count() == 0) return;

  IdentifierMapEntry* entry = mIdentifierMap.GetEntry(aName);
  if (!entry)  // Could be false if the element was anonymous, hence never added
    return;

  entry->RemoveNameElement(aElement);
  if (!entry->HasNameElement() &&
      !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
    IncrementExpandoGeneration(*this);
  }
}

void Document::AddToIdTable(Element* aElement, nsAtom* aId) {
  IdentifierMapEntry* entry = mIdentifierMap.PutEntry(aId);

  if (entry) { /* True except on OOM */
    if (nsGenericHTMLElement::ShouldExposeIdAsHTMLDocumentProperty(aElement) &&
        !entry->HasNameElement() &&
        !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
      IncrementExpandoGeneration(*this);
    }
    entry->AddIdElement(aElement);
  }
}

void Document::RemoveFromIdTable(Element* aElement, nsAtom* aId) {
  NS_ASSERTION(aId, "huhwhatnow?");

  // Speed up document teardown
  if (mIdentifierMap.Count() == 0) {
    return;
  }

  IdentifierMapEntry* entry = mIdentifierMap.GetEntry(aId);
  if (!entry)  // Can be null for XML elements with changing ids.
    return;

  entry->RemoveIdElement(aElement);
  if (nsGenericHTMLElement::ShouldExposeIdAsHTMLDocumentProperty(aElement) &&
      !entry->HasNameElement() &&
      !entry->HasIdElementExposedAsHTMLDocumentProperty()) {
    IncrementExpandoGeneration(*this);
  }
  if (entry->IsEmpty()) {
    mIdentifierMap.RemoveEntry(entry);
  }
}

void Document::SetPrincipals(nsIPrincipal* aNewPrincipal,
                             nsIPrincipal* aNewStoragePrincipal) {
  MOZ_ASSERT(!!aNewPrincipal == !!aNewStoragePrincipal);
  if (aNewPrincipal && mAllowDNSPrefetch && sDisablePrefetchHTTPSPref) {
    nsCOMPtr<nsIURI> uri;
    aNewPrincipal->GetURI(getter_AddRefs(uri));
    bool isHTTPS;
    if (!uri || NS_FAILED(uri->SchemeIs("https", &isHTTPS)) || isHTTPS) {
      mAllowDNSPrefetch = false;
    }
  }
  mNodeInfoManager->SetDocumentPrincipal(aNewPrincipal);
  mIntrinsicStoragePrincipal = aNewStoragePrincipal;

#ifdef DEBUG
  // Validate that the docgroup is set correctly by calling its getter and
  // triggering its sanity check.
  //
  // If we're setting the principal to null, we don't want to perform the check,
  // as the document is entering an intermediate state where it does not have a
  // principal. It will be given another real principal shortly which we will
  // check. It's not unsafe to have a document which has a null principal in the
  // same docgroup as another document, so this should not be a problem.
  if (aNewPrincipal) {
    GetDocGroup();
  }
#endif
}

#ifdef DEBUG
void Document::AssertDocGroupMatchesKey() const {
  // Sanity check that we have an up-to-date and accurate docgroup
  if (mDocGroup) {
    nsAutoCString docGroupKey;

    // GetKey() can fail, e.g. after the TLD service has shut down.
    nsresult rv = mozilla::dom::DocGroup::GetKey(NodePrincipal(), docGroupKey);
    if (NS_SUCCEEDED(rv)) {
      MOZ_ASSERT(mDocGroup->MatchesKey(docGroupKey));
    }
    // XXX: Check that the TabGroup is correct as well!
  }
}
#endif

nsresult Document::Dispatch(TaskCategory aCategory,
                            already_AddRefed<nsIRunnable>&& aRunnable) {
  // Note that this method may be called off the main thread.
  if (mDocGroup) {
    return mDocGroup->Dispatch(aCategory, std::move(aRunnable));
  }
  return DispatcherTrait::Dispatch(aCategory, std::move(aRunnable));
}

nsISerialEventTarget* Document::EventTargetFor(TaskCategory aCategory) const {
  if (mDocGroup) {
    return mDocGroup->EventTargetFor(aCategory);
  }
  return DispatcherTrait::EventTargetFor(aCategory);
}

AbstractThread* Document::AbstractMainThreadFor(
    mozilla::TaskCategory aCategory) {
  MOZ_ASSERT(NS_IsMainThread());
  if (mDocGroup) {
    return mDocGroup->AbstractMainThreadFor(aCategory);
  }
  return DispatcherTrait::AbstractMainThreadFor(aCategory);
}

void Document::NoteScriptTrackingStatus(const nsACString& aURL,
                                        bool aIsTracking) {
  if (aIsTracking) {
    mTrackingScripts.PutEntry(aURL);
  } else {
    MOZ_ASSERT(!mTrackingScripts.Contains(aURL));
  }
}

bool Document::IsScriptTracking(const nsACString& aURL) const {
  return mTrackingScripts.Contains(aURL);
}

NS_IMETHODIMP
Document::GetApplicationCache(nsIApplicationCache** aApplicationCache) {
  NS_IF_ADDREF(*aApplicationCache = mApplicationCache);
  return NS_OK;
}

NS_IMETHODIMP
Document::SetApplicationCache(nsIApplicationCache* aApplicationCache) {
  mApplicationCache = aApplicationCache;
  return NS_OK;
}

void Document::GetContentType(nsAString& aContentType) {
  CopyUTF8toUTF16(GetContentTypeInternal(), aContentType);
}

void Document::SetContentType(const nsAString& aContentType) {
  SetContentTypeInternal(NS_ConvertUTF16toUTF8(aContentType));
}

bool Document::GetAllowPlugins() {
  // First, we ask our docshell if it allows plugins.
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);

  if (docShell) {
    bool allowPlugins = false;
    docShell->GetAllowPlugins(&allowPlugins);
    if (!allowPlugins) {
      return false;
    }

    // If the docshell allows plugins, we check whether
    // we are sandboxed and plugins should not be allowed.
    if (mSandboxFlags & SANDBOXED_PLUGINS) {
      return false;
    }
  }

  FlashClassification classification = DocumentFlashClassification();
  if (classification == FlashClassification::Denied) {
    return false;
  }

  return true;
}

void Document::InitializeLocalization(nsTArray<nsString>& aResourceIds) {
  MOZ_ASSERT(!mDocumentL10n, "mDocumentL10n should not be initialized yet");

  DocumentL10n* l10n = new DocumentL10n(this);
  MOZ_ALWAYS_TRUE(l10n->Init(aResourceIds));
  mDocumentL10n = l10n;
}

DocumentL10n* Document::GetL10n() { return mDocumentL10n; }

bool Document::DocumentSupportsL10n(JSContext* aCx, JSObject* aObject) {
  nsCOMPtr<nsIPrincipal> callerPrincipal =
      nsContentUtils::SubjectPrincipal(aCx);
  return PrincipalAllowsL10n(callerPrincipal);
}

void Document::LocalizationLinkAdded(Element* aLinkElement) {
  if (!PrincipalAllowsL10n(NodePrincipal())) {
    return;
  }

  nsAutoString href;
  aLinkElement->GetAttr(kNameSpaceID_None, nsGkAtoms::href, href);
  // If the link is added after the DocumentL10n instance
  // has been initialized, just pass the resource ID to it.
  if (mDocumentL10n) {
    AutoTArray<nsString, 1> resourceIds;
    resourceIds.AppendElement(href);
    mDocumentL10n->AddResourceIds(resourceIds);
  } else if (mReadyState >= READYSTATE_INTERACTIVE) {
    // Otherwise, if the document has already been parsed
    // we need to lazily initialize the localization.
    AutoTArray<nsString, 1> resourceIds;
    resourceIds.AppendElement(href);
    InitializeLocalization(resourceIds);
    mDocumentL10n->TriggerInitialDocumentTranslation();
  } else {
    // Otherwise, we're still parsing the document.
    // In that case, add it to the pending list. This list
    // will be resolved once the end of l10n resource
    // container is reached.
    mL10nResources.AppendElement(href);

    mPendingInitialTranslation = true;
  }
}

void Document::LocalizationLinkRemoved(Element* aLinkElement) {
  if (!PrincipalAllowsL10n(NodePrincipal())) {
    return;
  }

  nsAutoString href;
  aLinkElement->GetAttr(kNameSpaceID_None, nsGkAtoms::href, href);
  if (mDocumentL10n) {
    AutoTArray<nsString, 1> resourceIds;
    resourceIds.AppendElement(href);
    uint32_t remaining = mDocumentL10n->RemoveResourceIds(resourceIds);
    if (remaining == 0) {
      mDocumentL10n = nullptr;
    }
  } else {
    mL10nResources.RemoveElement(href);
  }
}

/**
 * This method should be called once the end of the l10n
 * resource container has been parsed.
 *
 * In XUL this is the end of the first </linkset>,
 * In XHTML/HTML this is the end of </head>.
 *
 * This milestone is used to allow for batch
 * localization context I/O and building done
 * once when all resources in the document have been
 * collected.
 */
void Document::OnL10nResourceContainerParsed() {
  if (!mL10nResources.IsEmpty()) {
    InitializeLocalization(mL10nResources);
    mL10nResources.Clear();
  }
}

void Document::TriggerInitialDocumentTranslation() {
  // Let's call it again, in case the resource
  // container has not been closed, and only
  // now we're closing the document.
  OnL10nResourceContainerParsed();

  if (mDocumentL10n) {
    mDocumentL10n->TriggerInitialDocumentTranslation();
  }
}

void Document::InitialDocumentTranslationCompleted() {
  mPendingInitialTranslation = false;
}

bool Document::IsWebAnimationsEnabled(JSContext* aCx, JSObject* /*unused*/) {
  MOZ_ASSERT(NS_IsMainThread());

  return nsContentUtils::IsSystemCaller(aCx) ||
         StaticPrefs::dom_animations_api_core_enabled();
}

bool Document::IsWebAnimationsEnabled(CallerType aCallerType) {
  MOZ_ASSERT(NS_IsMainThread());

  return aCallerType == dom::CallerType::System ||
         StaticPrefs::dom_animations_api_core_enabled();
}

bool Document::IsWebAnimationsGetAnimationsEnabled(JSContext* aCx,
                                                   JSObject* /*unused*/
) {
  MOZ_ASSERT(NS_IsMainThread());

  return nsContentUtils::IsSystemCaller(aCx) ||
         StaticPrefs::dom_animations_api_getAnimations_enabled();
}

bool Document::AreWebAnimationsImplicitKeyframesEnabled(JSContext* aCx,
                                                        JSObject* /*unused*/
) {
  MOZ_ASSERT(NS_IsMainThread());

  return nsContentUtils::IsSystemCaller(aCx) ||
         StaticPrefs::dom_animations_api_implicit_keyframes_enabled();
}

bool Document::AreWebAnimationsTimelinesEnabled(JSContext* aCx,
                                                JSObject* /*unused*/
) {
  MOZ_ASSERT(NS_IsMainThread());

  return nsContentUtils::IsSystemCaller(aCx) ||
         StaticPrefs::dom_animations_api_timelines_enabled();
}

DocumentTimeline* Document::Timeline() {
  if (!mDocumentTimeline) {
    mDocumentTimeline = new DocumentTimeline(this, TimeDuration(0));
  }

  return mDocumentTimeline;
}

void Document::GetAnimations(nsTArray<RefPtr<Animation>>& aAnimations) {
  // Hold a strong ref for the root element since Element::GetAnimations() calls
  // FlushPendingNotifications() which may destroy the element.
  RefPtr<Element> root = GetRootElement();
  if (!root) {
    return;
  }
  AnimationFilter filter;
  filter.mSubtree = true;
  root->GetAnimations(filter, aAnimations);
}

SVGSVGElement* Document::GetSVGRootElement() const {
  Element* root = GetRootElement();
  if (!root || !root->IsSVGElement(nsGkAtoms::svg)) {
    return nullptr;
  }
  return static_cast<SVGSVGElement*>(root);
}

/* Return true if the document is in the focused top-level window, and is an
 * ancestor of the focused DOMWindow. */
bool Document::HasFocus(ErrorResult& rv) const {
  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  if (!fm) {
    rv.Throw(NS_ERROR_NOT_AVAILABLE);
    return false;
  }

  // Is there a focused DOMWindow?
  nsCOMPtr<mozIDOMWindowProxy> focusedWindow;
  fm->GetFocusedWindow(getter_AddRefs(focusedWindow));
  if (!focusedWindow) {
    return false;
  }

  nsPIDOMWindowOuter* piWindow = nsPIDOMWindowOuter::From(focusedWindow);

  // Are we an ancestor of the focused DOMWindow?
  for (Document* currentDoc = piWindow->GetDoc(); currentDoc;
       currentDoc = currentDoc->GetParentDocument()) {
    if (currentDoc == this) {
      // Yes, we are an ancestor
      return true;
    }
  }

  return false;
}

TimeStamp Document::LastFocusTime() const { return mLastFocusTime; }

void Document::SetLastFocusTime(const TimeStamp& aFocusTime) {
  MOZ_DIAGNOSTIC_ASSERT(!aFocusTime.IsNull());
  MOZ_DIAGNOSTIC_ASSERT(mLastFocusTime.IsNull() ||
                        aFocusTime >= mLastFocusTime);
  mLastFocusTime = aFocusTime;
}

void Document::GetReferrer(nsAString& aReferrer) const {
  if (mIsSrcdocDocument && mParentDocument)
    mParentDocument->GetReferrer(aReferrer);
  else
    CopyUTF8toUTF16(mReferrer, aReferrer);
}

void Document::GetCookie(nsAString& aCookie, ErrorResult& rv) {
  aCookie.Truncate();  // clear current cookie in case service fails;
                       // no cookie isn't an error condition.

  if (mDisableCookieAccess) {
    return;
  }

  // If the document's sandboxed origin flag is set, access to read cookies
  // is prohibited.
  if (mSandboxFlags & SANDBOXED_ORIGIN) {
    rv.Throw(NS_ERROR_DOM_SECURITY_ERR);
    return;
  }

  nsContentUtils::StorageAccess storageAccess =
      nsContentUtils::StorageAllowedForDocument(this);
  if (storageAccess == nsContentUtils::StorageAccess::eDeny) {
    return;
  }

  if (storageAccess == nsContentUtils::StorageAccess::ePartitionedOrDeny &&
      !StaticPrefs::privacy_storagePrincipal_enabledForTrackers()) {
    return;
  }

  // If the document is a cookie-averse Document... return the empty string.
  if (IsCookieAverse()) {
    return;
  }

  // not having a cookie service isn't an error
  nsCOMPtr<nsICookieService> service =
      do_GetService(NS_COOKIESERVICE_CONTRACTID);
  if (service) {
    // Get a URI from the document principal. We use the original
    // codebase in case the codebase was changed by SetDomain
    nsCOMPtr<nsIURI> codebaseURI;
    NodePrincipal()->GetURI(getter_AddRefs(codebaseURI));

    if (!codebaseURI) {
      // Document's principal is not a codebase (may be system), so
      // can't set cookies

      return;
    }

    nsCOMPtr<nsIChannel> channel(mChannel);
    if (!channel) {
      channel = CreateDummyChannelForCookies(codebaseURI);
      if (!channel) {
        return;
      }
    }

    nsCString cookie;
    service->GetCookieString(codebaseURI, channel, getter_Copies(cookie));
    // CopyUTF8toUTF16 doesn't handle error
    // because it assumes that the input is valid.
    UTF_8_ENCODING->DecodeWithoutBOMHandling(cookie, aCookie);
  }
}

void Document::SetCookie(const nsAString& aCookie, ErrorResult& rv) {
  if (mDisableCookieAccess) {
    return;
  }

  // If the document's sandboxed origin flag is set, access to write cookies
  // is prohibited.
  if (mSandboxFlags & SANDBOXED_ORIGIN) {
    rv.Throw(NS_ERROR_DOM_SECURITY_ERR);
    return;
  }

  nsContentUtils::StorageAccess storageAccess =
      nsContentUtils::StorageAllowedForDocument(this);
  if (storageAccess == nsContentUtils::StorageAccess::eDeny) {
    return;
  }

  if (storageAccess == nsContentUtils::StorageAccess::ePartitionedOrDeny &&
      !StaticPrefs::privacy_storagePrincipal_enabledForTrackers()) {
    return;
  }

  // If the document is a cookie-averse Document... do nothing.
  if (IsCookieAverse()) {
    return;
  }

  // not having a cookie service isn't an error
  nsCOMPtr<nsICookieService> service =
      do_GetService(NS_COOKIESERVICE_CONTRACTID);
  if (service && mDocumentURI) {
    // The code for getting the URI matches Navigator::CookieEnabled
    nsCOMPtr<nsIURI> codebaseURI;
    NodePrincipal()->GetURI(getter_AddRefs(codebaseURI));

    if (!codebaseURI) {
      // Document's principal is not a codebase (may be system), so
      // can't set cookies

      return;
    }

    nsCOMPtr<nsIChannel> channel(mChannel);
    if (!channel) {
      channel = CreateDummyChannelForCookies(codebaseURI);
      if (!channel) {
        return;
      }
    }

    NS_ConvertUTF16toUTF8 cookie(aCookie);
    service->SetCookieString(codebaseURI, nullptr, cookie.get(), channel);
  }
}

already_AddRefed<nsIChannel> Document::CreateDummyChannelForCookies(
    nsIURI* aCodebaseURI) {
  // The cookie service reads the privacy status of the channel we pass to it in
  // order to determine which cookie database to query.  In some cases we don't
  // have a proper channel to hand it to the cookie service though.  This
  // function creates a dummy channel that is not used to load anything, for the
  // sole purpose of handing it to the cookie service.  DO NOT USE THIS CHANNEL
  // FOR ANY OTHER PURPOSE.
  MOZ_ASSERT(!mChannel);

  // The following channel is never openend, so it does not matter what
  // securityFlags we pass; let's follow the principle of least privilege.
  nsCOMPtr<nsIChannel> channel;
  NS_NewChannel(getter_AddRefs(channel), aCodebaseURI, this,
                nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
                nsIContentPolicy::TYPE_INVALID);
  nsCOMPtr<nsIPrivateBrowsingChannel> pbChannel = do_QueryInterface(channel);
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
  nsCOMPtr<nsILoadContext> loadContext = do_QueryInterface(docShell);
  if (!pbChannel || !loadContext) {
    return nullptr;
  }
  pbChannel->SetPrivate(loadContext->UsePrivateBrowsing());

  return channel.forget();
}

mozilla::net::ReferrerPolicy Document::GetReferrerPolicy() const {
  if (mIsSrcdocDocument && mParentDocument &&
      mReferrerPolicy == mozilla::net::RP_Unset) {
    return mParentDocument->GetReferrerPolicy();
  }
  return mReferrerPolicy;
}

nsresult Document::GetSrcdocData(nsAString& aSrcdocData) {
  if (mIsSrcdocDocument) {
    nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(mChannel);
    if (inStrmChan) {
      return inStrmChan->GetSrcdocData(aSrcdocData);
    }
  }
  aSrcdocData = VoidString();
  return NS_OK;
}

Nullable<WindowProxyHolder> Document::GetDefaultView() const {
  nsPIDOMWindowOuter* win = GetWindow();
  if (!win) {
    return nullptr;
  }
  return WindowProxyHolder(win->GetBrowsingContext());
}

Element* Document::GetActiveElement() {
  // Get the focused element.
  Element* focusedElement = GetRetargetedFocusedElement();
  if (focusedElement) {
    return focusedElement;
  }

  // No focused element anywhere in this document.  Try to get the BODY.
  if (IsHTMLOrXHTML()) {
    Element* bodyElement = AsHTMLDocument()->GetBody();
    if (bodyElement) {
      return bodyElement;
    }
    // Special case to handle the transition to browser.xhtml where there is
    // currently not a body element, but we need to match the XUL behavior.
    // This should be removed when bug 1492582 is resolved.
    if (nsContentUtils::IsChromeDoc(this)) {
      Element* docElement = GetDocumentElement();
      if (docElement && docElement->IsXULElement()) {
        return docElement;
      }
    }
    // Because of IE compatibility, return null when html document doesn't have
    // a body.
    return nullptr;
  }

  // If we couldn't get a BODY, return the root element.
  return GetDocumentElement();
}

Element* Document::GetCurrentScript() {
  nsCOMPtr<Element> el(do_QueryInterface(ScriptLoader()->GetCurrentScript()));
  return el;
}

void Document::ReleaseCapture() const {
  // only release the capture if the caller can access it. This prevents a
  // page from stopping a scrollbar grab for example.
  nsCOMPtr<nsINode> node = PresShell::GetCapturingContent();
  if (node && nsContentUtils::CanCallerAccess(node)) {
    PresShell::ReleaseCapturingContent();
  }
}

already_AddRefed<nsIURI> Document::GetBaseURI(bool aTryUseXHRDocBaseURI) const {
  nsCOMPtr<nsIURI> uri;
  if (aTryUseXHRDocBaseURI && mChromeXHRDocBaseURI) {
    uri = mChromeXHRDocBaseURI;
  } else {
    uri = GetDocBaseURI();
  }

  return uri.forget();
}

void Document::SetBaseURI(nsIURI* aURI) {
  if (!aURI && !mDocumentBaseURI) {
    return;
  }

  // Don't do anything if the URI wasn't actually changed.
  if (aURI && mDocumentBaseURI) {
    bool equalBases = false;
    mDocumentBaseURI->Equals(aURI, &equalBases);
    if (equalBases) {
      return;
    }
  }

  mDocumentBaseURI = aURI;
  RefreshLinkHrefs();
}

URLExtraData* Document::DefaultStyleAttrURLData() {
  MOZ_ASSERT(NS_IsMainThread());
  nsIURI* baseURI = GetDocBaseURI();
  nsIURI* docURI = GetDocumentURI();
  nsIPrincipal* principal = NodePrincipal();
  mozilla::net::ReferrerPolicy policy = GetReferrerPolicy();
  if (!mCachedURLData || mCachedURLData->BaseURI() != baseURI ||
      mCachedURLData->GetReferrer() != docURI ||
      mCachedURLData->GetReferrerPolicy() != policy ||
      mCachedURLData->Principal() != principal) {
    mCachedURLData = new URLExtraData(baseURI, docURI, principal, policy);
  }
  return mCachedURLData;
}

void Document::SetDocumentCharacterSet(NotNull<const Encoding*> aEncoding) {
  if (mCharacterSet != aEncoding) {
    mCharacterSet = aEncoding;
    mEncodingMenuDisabled = aEncoding == UTF_8_ENCODING;
    RecomputeLanguageFromCharset();

    if (nsPresContext* context = GetPresContext()) {
      context->DispatchCharSetChange(aEncoding);
    }
  }
}

void Document::GetSandboxFlagsAsString(nsAString& aFlags) {
  nsContentUtils::SandboxFlagsToString(mSandboxFlags, aFlags);
}

void Document::GetHeaderData(nsAtom* aHeaderField, nsAString& aData) const {
  aData.Truncate();
  const DocHeaderData* data = mHeaderData;
  while (data) {
    if (data->mField == aHeaderField) {
      aData = data->mData;

      break;
    }
    data = data->mNext;
  }
}

void Document::SetHeaderData(nsAtom* aHeaderField, const nsAString& aData) {
  if (!aHeaderField) {
    NS_ERROR("null headerField");
    return;
  }

  if (!mHeaderData) {
    if (!aData.IsEmpty()) {  // don't bother storing empty string
      mHeaderData = new DocHeaderData(aHeaderField, aData);
    }
  } else {
    DocHeaderData* data = mHeaderData;
    DocHeaderData** lastPtr = &mHeaderData;
    bool found = false;
    do {  // look for existing and replace
      if (data->mField == aHeaderField) {
        if (!aData.IsEmpty()) {
          data->mData.Assign(aData);
        } else {  // don't store empty string
          *lastPtr = data->mNext;
          data->mNext = nullptr;
          delete data;
        }
        found = true;

        break;
      }
      lastPtr = &(data->mNext);
      data = *lastPtr;
    } while (data);

    if (!aData.IsEmpty() && !found) {
      // didn't find, append
      *lastPtr = new DocHeaderData(aHeaderField, aData);
    }
  }

  if (aHeaderField == nsGkAtoms::headerContentLanguage) {
    CopyUTF16toUTF8(aData, mContentLanguage);
    mMayNeedFontPrefsUpdate = true;
    if (auto* presContext = GetPresContext()) {
      presContext->ContentLanguageChanged();
    }
  }

  if (aHeaderField == nsGkAtoms::headerDefaultStyle) {
    SetPreferredStyleSheetSet(aData);
  }

  if (aHeaderField == nsGkAtoms::refresh) {
    // We get into this code before we have a script global yet, so get to
    // our container via mDocumentContainer.
    nsCOMPtr<nsIRefreshURI> refresher(mDocumentContainer);
    if (refresher) {
      // Note: using mDocumentURI instead of mBaseURI here, for consistency
      // (used to just use the current URI of our webnavigation, but that
      // should really be the same thing).  Note that this code can run
      // before the current URI of the webnavigation has been updated, so we
      // can't assert equality here.
      refresher->SetupRefreshURIFromHeader(mDocumentURI, NodePrincipal(),
                                           NS_ConvertUTF16toUTF8(aData));
    }
  }

  if (aHeaderField == nsGkAtoms::headerDNSPrefetchControl &&
      mAllowDNSPrefetch) {
    // Chromium treats any value other than 'on' (case insensitive) as 'off'.
    mAllowDNSPrefetch = aData.IsEmpty() || aData.LowerCaseEqualsLiteral("on");
  }

  if (aHeaderField == nsGkAtoms::viewport ||
      aHeaderField == nsGkAtoms::handheldFriendly ||
      aHeaderField == nsGkAtoms::viewport_minimum_scale ||
      aHeaderField == nsGkAtoms::viewport_maximum_scale ||
      aHeaderField == nsGkAtoms::viewport_initial_scale ||
      aHeaderField == nsGkAtoms::viewport_height ||
      aHeaderField == nsGkAtoms::viewport_width ||
      aHeaderField == nsGkAtoms::viewport_user_scalable) {
    mViewportType = Unknown;
  }

  // Referrer policy spec says to ignore any empty referrer policies.
  if (aHeaderField == nsGkAtoms::referrer && !aData.IsEmpty()) {
    enum mozilla::net::ReferrerPolicy policy =
        mozilla::net::ReferrerPolicyFromString(aData);
    // If policy is not the empty string, then set element's node document's
    // referrer policy to policy
    if (policy != mozilla::net::RP_Unset) {
      // Referrer policy spec (section 6.1) says that we always use the newest
      // referrer policy we find
      mReferrerPolicy = policy;
      mReferrerPolicySet = true;
    }
  }

  if (aHeaderField == nsGkAtoms::headerReferrerPolicy && !aData.IsEmpty()) {
    enum mozilla::net::ReferrerPolicy policy =
        nsContentUtils::GetReferrerPolicyFromHeader(aData);
    if (policy != mozilla::net::RP_Unset) {
      mReferrerPolicy = policy;
      mReferrerPolicySet = true;
    }
  }
}
void Document::TryChannelCharset(nsIChannel* aChannel, int32_t& aCharsetSource,
                                 NotNull<const Encoding*>& aEncoding,
                                 nsHtml5TreeOpExecutor* aExecutor) {
  if (aChannel) {
    nsAutoCString charsetVal;
    nsresult rv = aChannel->GetContentCharset(charsetVal);
    if (NS_SUCCEEDED(rv)) {
      const Encoding* preferred = Encoding::ForLabel(charsetVal);
      if (preferred) {
        aEncoding = WrapNotNull(preferred);
        aCharsetSource = kCharsetFromChannel;
        return;
      } else if (aExecutor && !charsetVal.IsEmpty()) {
        aExecutor->ComplainAboutBogusProtocolCharset(this);
      }
    }
  }
}

static inline void AssertNoStaleServoDataIn(nsINode& aSubtreeRoot) {
#ifdef DEBUG
  for (nsINode* node : ShadowIncludingTreeIterator(aSubtreeRoot)) {
    const Element* element = Element::FromNode(node);
    if (!element) {
      continue;
    }
    MOZ_ASSERT(!element->HasServoData());
    if (nsXBLBinding* binding = element->GetXBLBinding()) {
      if (nsXBLBinding* bindingWithContent = binding->GetBindingWithContent()) {
        nsIContent* content = bindingWithContent->GetAnonymousContent();
        // Need to do this instead of just AssertNoStaleServoDataIn(*content),
        // because the parent of the children of the <content> element isn't the
        // <content> element, but the bound element, and that confuses
        // GetNextNode a lot.
        MOZ_ASSERT(!content->AsElement()->HasServoData());
        for (nsINode* child = content->GetFirstChild(); child;
             child = child->GetNextSibling()) {
          AssertNoStaleServoDataIn(*child);
        }
      }
    }
  }
#endif
}

already_AddRefed<PresShell> Document::CreatePresShell(
    nsPresContext* aContext, nsViewManager* aViewManager) {
  MOZ_ASSERT(!mPresShell, "We have a presshell already!");

  NS_ENSURE_FALSE(GetBFCacheEntry(), nullptr);

  AssertNoStaleServoDataIn(*this);

  RefPtr<PresShell> presShell = new PresShell;
  // Note: we don't hold a ref to the shell (it holds a ref to us)
  mPresShell = presShell;

  bool hadStyleSheets = mStyleSetFilled;
  if (!hadStyleSheets) {
    FillStyleSet();
  }

  presShell->Init(this, aContext, aViewManager);

  if (hadStyleSheets) {
    // Gaining a shell causes changes in how media queries are evaluated, so
    // invalidate that.
    aContext->MediaFeatureValuesChanged({MediaFeatureChange::kAllChanges});
  }

  // Make sure to never paint if we belong to an invisible DocShell.
  nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
  if (docShell && docShell->IsInvisible()) {
    presShell->SetNeverPainting(true);
  }

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug,
          ("DOCUMENT %p with PressShell %p and DocShell %p", this,
           presShell.get(), docShell.get()));

  mExternalResourceMap.ShowViewers();

  UpdateFrameRequestCallbackSchedulingState();

  // Now that we have a shell, we might have @font-face rules (the presence of a
  // shell may change which rules apply to us). We don't need to do anything
  // like EnsureStyleFlush or such, there's nothing to update yet and when stuff
  // is ready to update we'll flush the font set.
  MarkUserFontSetDirty();

  return presShell.forget();
}

void Document::UpdateFrameRequestCallbackSchedulingState(
    PresShell* aOldPresShell) {
  // If the condition for shouldBeScheduled changes to depend on some other
  // variable, add UpdateFrameRequestCallbackSchedulingState() calls to the
  // places where that variable can change.
  bool shouldBeScheduled = mPresShell && IsEventHandlingEnabled() &&
                           !mFrameRequestCallbacks.IsEmpty();
  if (shouldBeScheduled == mFrameRequestCallbacksScheduled) {
    // nothing to do
    return;
  }

  PresShell* presShell = aOldPresShell ? aOldPresShell : mPresShell;
  MOZ_RELEASE_ASSERT(presShell);

  nsRefreshDriver* rd = presShell->GetPresContext()->RefreshDriver();
  if (shouldBeScheduled) {
    rd->ScheduleFrameRequestCallbacks(this);
  } else {
    rd->RevokeFrameRequestCallbacks(this);
  }

  mFrameRequestCallbacksScheduled = shouldBeScheduled;
}

void Document::TakeFrameRequestCallbacks(nsTArray<FrameRequest>& aCallbacks) {
  MOZ_ASSERT(aCallbacks.IsEmpty());
  aCallbacks.SwapElements(mFrameRequestCallbacks);
  mCanceledFrameRequestCallbacks.clear();
  // No need to manually remove ourselves from the refresh driver; it will
  // handle that part.  But we do have to update our state.
  mFrameRequestCallbacksScheduled = false;
}

bool Document::ShouldThrottleFrameRequests() {
  if (mStaticCloneCount > 0) {
    // Even if we're not visible, a static clone may be, so run at full speed.
    return false;
  }

  if (Hidden()) {
    // We're not visible (probably in a background tab or the bf cache).
    return true;
  }

  if (!mPresShell) {
    return false;  // Can't do anything smarter.
  }

  nsIFrame* frame = mPresShell->GetRootFrame();
  if (!frame) {
    return false;  // Can't do anything smarter.
  }

  nsIFrame* displayRootFrame = nsLayoutUtils::GetDisplayRootFrame(frame);
  if (!displayRootFrame) {
    return false;  // Can't do anything smarter.
  }

  if (!displayRootFrame->DidPaintPresShell(mPresShell)) {
    // We didn't get painted during the last paint, so we're not visible.
    // Throttle. Note that because we have to paint this document at least
    // once to unthrottle it, we will drop one requestAnimationFrame frame
    // when a document that previously wasn't visible scrolls into view. This
    // is acceptable since it would happen outside the viewport on APZ
    // platforms and is unlikely to be human-perceivable on non-APZ platforms.
    return true;
  }

  // We got painted during the last paint, so run at full speed.
  return false;
}

void Document::DeletePresShell() {
  mExternalResourceMap.HideViewers();
  if (nsPresContext* presContext = mPresShell->GetPresContext()) {
    presContext->RefreshDriver()->CancelPendingFullscreenEvents(this);
  }

  // When our shell goes away, request that all our images be immediately
  // discarded, so we don't carry around decoded image data for a document we
  // no longer intend to paint.
  ImageTracker()->RequestDiscardAll();

  // Now that we no longer have a shell, we need to forget about any FontFace
  // objects for @font-face rules that came from the style set. There's no need
  // to call EnsureStyleFlush either, the shell is going away anyway, so there's
  // no point on it.
  MarkUserFontSetDirty();

  if (mResizeObserverController) {
    mResizeObserverController->ShellDetachedFromDocument();
  }

  PresShell* oldPresShell = mPresShell;
  mPresShell = nullptr;
  UpdateFrameRequestCallbackSchedulingState(oldPresShell);

  ClearStaleServoData();
  AssertNoStaleServoDataIn(*this);

  mStyleSet->ShellDetachedFromDocument();
  mStyleSetFilled = false;
  mQuirkSheetAdded = false;
  mContentEditableSheetAdded = false;
  mDesignModeSheetAdded = false;
}

void Document::SetBFCacheEntry(nsIBFCacheEntry* aEntry) {
  MOZ_ASSERT(IsBFCachingAllowed() || !aEntry, "You should have checked!");

  if (mPresShell) {
    if (aEntry) {
      mPresShell->StopObservingRefreshDriver();
    } else if (mBFCacheEntry) {
      mPresShell->StartObservingRefreshDriver();
    }
  }
  mBFCacheEntry = aEntry;
}

static void SubDocClearEntry(PLDHashTable* table, PLDHashEntryHdr* entry) {
  SubDocMapEntry* e = static_cast<SubDocMapEntry*>(entry);

  NS_RELEASE(e->mKey);
  if (e->mSubDocument) {
    e->mSubDocument->SetParentDocument(nullptr);
    NS_RELEASE(e->mSubDocument);
  }
}

static void SubDocInitEntry(PLDHashEntryHdr* entry, const void* key) {
  SubDocMapEntry* e =
      const_cast<SubDocMapEntry*>(static_cast<const SubDocMapEntry*>(entry));

  e->mKey = const_cast<Element*>(static_cast<const Element*>(key));
  NS_ADDREF(e->mKey);

  e->mSubDocument = nullptr;
}

nsresult Document::SetSubDocumentFor(Element* aElement, Document* aSubDoc) {
  NS_ENSURE_TRUE(aElement, NS_ERROR_UNEXPECTED);

  if (!aSubDoc) {
    // aSubDoc is nullptr, remove the mapping

    if (mSubDocuments) {
      Document* subDoc = GetSubDocumentFor(aElement);
      if (subDoc) {
        subDoc->SetAllowPaymentRequest(false);
      }
      mSubDocuments->Remove(aElement);
    }
  } else {
    if (!mSubDocuments) {
      // Create a new hashtable

      static const PLDHashTableOps hash_table_ops = {
          PLDHashTable::HashVoidPtrKeyStub, PLDHashTable::MatchEntryStub,
          PLDHashTable::MoveEntryStub, SubDocClearEntry, SubDocInitEntry};

      mSubDocuments = new PLDHashTable(&hash_table_ops, sizeof(SubDocMapEntry));
    }

    // Add a mapping to the hash table
    auto entry =
        static_cast<SubDocMapEntry*>(mSubDocuments->Add(aElement, fallible));

    if (!entry) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    if (entry->mSubDocument) {
      entry->mSubDocument->SetAllowPaymentRequest(false);
      entry->mSubDocument->SetParentDocument(nullptr);

      // Release the old sub document
      NS_RELEASE(entry->mSubDocument);
    }

    entry->mSubDocument = aSubDoc;
    NS_ADDREF(entry->mSubDocument);

    // set allowpaymentrequest for the binding subdocument
    if (!mAllowPaymentRequest) {
      aSubDoc->SetAllowPaymentRequest(false);
    } else {
      nsresult rv = nsContentUtils::CheckSameOrigin(aElement, aSubDoc);
      if (NS_SUCCEEDED(rv)) {
        aSubDoc->SetAllowPaymentRequest(true);
      } else {
        if (aElement->IsHTMLElement(nsGkAtoms::iframe) &&
            aElement->GetBoolAttr(nsGkAtoms::allowpaymentrequest)) {
          aSubDoc->SetAllowPaymentRequest(true);
        } else {
          aSubDoc->SetAllowPaymentRequest(false);
        }
      }
    }

    aSubDoc->SetParentDocument(this);
  }

  return NS_OK;
}

Document* Document::GetSubDocumentFor(nsIContent* aContent) const {
  if (mSubDocuments && aContent->IsElement()) {
    auto entry = static_cast<SubDocMapEntry*>(
        mSubDocuments->Search(aContent->AsElement()));

    if (entry) {
      return entry->mSubDocument;
    }
  }

  return nullptr;
}

Element* Document::FindContentForSubDocument(Document* aDocument) const {
  NS_ENSURE_TRUE(aDocument, nullptr);

  if (!mSubDocuments) {
    return nullptr;
  }

  for (auto iter = mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
    auto entry = static_cast<SubDocMapEntry*>(iter.Get());
    if (entry->mSubDocument == aDocument) {
      return entry->mKey;
    }
  }
  return nullptr;
}

bool Document::IsNodeOfType(uint32_t aFlags) const { return false; }

Element* Document::GetRootElement() const {
  return (mCachedRootElement && mCachedRootElement->GetParentNode() == this)
             ? mCachedRootElement
             : GetRootElementInternal();
}

Element* Document::GetUnfocusedKeyEventTarget() { return GetRootElement(); }

Element* Document::GetRootElementInternal() const {
  // We invoke GetRootElement() immediately before the servo traversal, so we
  // should always have a cache hit from Servo.
  MOZ_ASSERT(NS_IsMainThread());

  // Loop backwards because any non-elements, such as doctypes and PIs
  // are likely to appear before the root element.
  for (nsIContent* child = GetLastChild(); child;
       child = child->GetPreviousSibling()) {
    if (Element* element = Element::FromNode(child)) {
      const_cast<Document*>(this)->mCachedRootElement = element;
      return element;
    }
  }

  const_cast<Document*>(this)->mCachedRootElement = nullptr;
  return nullptr;
}

nsresult Document::InsertChildBefore(nsIContent* aKid, nsIContent* aBeforeThis,
                                     bool aNotify) {
  if (aKid->IsElement() && GetRootElement()) {
    NS_WARNING("Inserting root element when we already have one");
    return NS_ERROR_DOM_HIERARCHY_REQUEST_ERR;
  }

  return nsINode::InsertChildBefore(aKid, aBeforeThis, aNotify);
}

void Document::RemoveChildNode(nsIContent* aKid, bool aNotify) {
  if (aKid->IsElement()) {
    // Destroy the link map up front before we mess with the child list.
    DestroyElementMaps();
  }

  // Preemptively clear mCachedRootElement, since we may be about to remove it
  // from our child list, and we don't want to return this maybe-obsolete value
  // from any GetRootElement() calls that happen inside of RemoveChildNode().
  // (NOTE: for this to be useful, RemoveChildNode() must NOT trigger any
  // GetRootElement() calls until after it's removed the child from mChildren.
  // Any call before that point would restore this soon-to-be-obsolete cached
  // answer, and our clearing here would be fruitless.)
  mCachedRootElement = nullptr;
  nsINode::RemoveChildNode(aKid, aNotify);
  MOZ_ASSERT(mCachedRootElement != aKid,
             "Stale pointer in mCachedRootElement, after we tried to clear it "
             "(maybe somebody called GetRootElement() too early?)");
}

void Document::AddStyleSheetToStyleSets(StyleSheet* aSheet) {
  if (mStyleSetFilled) {
    mStyleSet->AddDocStyleSheet(aSheet);
    ApplicableStylesChanged();
  }
}

void Document::RecordShadowStyleChange(ShadowRoot& aShadowRoot) {
  mStyleSet->RecordShadowStyleChange(aShadowRoot);
  ApplicableStylesChanged();
}

void Document::ApplicableStylesChanged() {
  // TODO(emilio): if we decide to resolve style in display: none iframes, then
  // we need to always track style changes and remove the mStyleSetFilled.
  if (!mStyleSetFilled) {
    return;
  }

  MarkUserFontSetDirty();
  PresShell* ps = GetPresShell();
  if (!ps) {
    return;
  }

  ps->EnsureStyleFlush();
  nsPresContext* pc = ps->GetPresContext();
  if (!pc) {
    return;
  }

  pc->MarkCounterStylesDirty();
  pc->MarkFontFeatureValuesDirty();
  pc->RestyleManager()->NextRestyleIsForCSSRuleChanges();
}

#define DO_STYLESHEET_NOTIFICATION(className, type, memberName, argName) \
  do {                                                                   \
    className##Init init;                                                \
    init.mBubbles = true;                                                \
    init.mCancelable = true;                                             \
    init.mStylesheet = aSheet;                                           \
    init.memberName = argName;                                           \
                                                                         \
    RefPtr<className> event =                                            \
        className::Constructor(this, NS_LITERAL_STRING(type), init);     \
    event->SetTrusted(true);                                             \
    event->SetTarget(this);                                              \
    RefPtr<AsyncEventDispatcher> asyncDispatcher =                       \
        new AsyncEventDispatcher(this, event);                           \
    asyncDispatcher->mOnlyChromeDispatch = ChromeOnlyDispatch::eYes;     \
    asyncDispatcher->PostDOMEvent();                                     \
  } while (0);

void Document::NotifyStyleSheetAdded(StyleSheet* aSheet, bool aDocumentSheet) {
  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleSheetChangeEvent, "StyleSheetAdded",
                               mDocumentSheet, aDocumentSheet);
  }
}

void Document::NotifyStyleSheetRemoved(StyleSheet* aSheet,
                                       bool aDocumentSheet) {
  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleSheetChangeEvent, "StyleSheetRemoved",
                               mDocumentSheet, aDocumentSheet);
  }
}

void Document::RemoveStyleSheetFromStyleSets(StyleSheet* aSheet) {
  if (mStyleSetFilled) {
    mStyleSet->RemoveDocStyleSheet(aSheet);
    ApplicableStylesChanged();
  }
}

void Document::RemoveStyleSheet(StyleSheet* aSheet) {
  MOZ_ASSERT(aSheet);
  RefPtr<StyleSheet> sheet = DocumentOrShadowRoot::RemoveSheet(*aSheet);

  if (!sheet) {
    NS_ASSERTION(mInUnlinkOrDeletion, "stylesheet not found");
    return;
  }

  if (!mIsGoingAway) {
    if (sheet->IsApplicable()) {
      RemoveStyleSheetFromStyleSets(sheet);
    }

    NotifyStyleSheetRemoved(sheet, true);
  }

  sheet->ClearAssociatedDocumentOrShadowRoot();
}

void Document::InsertSheetAt(size_t aIndex, StyleSheet& aSheet) {
  DocumentOrShadowRoot::InsertSheetAt(aIndex, aSheet);

  if (aSheet.IsApplicable()) {
    AddStyleSheetToStyleSets(&aSheet);
  }

  NotifyStyleSheetAdded(&aSheet, true);
}

void Document::SetStyleSheetApplicableState(StyleSheet* aSheet,
                                            bool aApplicable) {
  MOZ_ASSERT(aSheet, "null arg");

  // If we're actually in the document style sheet list
  if (mStyleSheets.IndexOf(aSheet) != mStyleSheets.NoIndex) {
    if (aApplicable) {
      AddStyleSheetToStyleSets(aSheet);
    } else {
      RemoveStyleSheetFromStyleSets(aSheet);
    }
  }

  if (StyleSheetChangeEventsEnabled()) {
    DO_STYLESHEET_NOTIFICATION(StyleSheetApplicableStateChangeEvent,
                               "StyleSheetApplicableStateChanged", mApplicable,
                               aApplicable);
  }

  if (!mSSApplicableStateNotificationPending) {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    nsCOMPtr<nsIRunnable> notification = NewRunnableMethod(
        "Document::NotifyStyleSheetApplicableStateChanged", this,
        &Document::NotifyStyleSheetApplicableStateChanged);
    mSSApplicableStateNotificationPending =
        NS_SUCCEEDED(Dispatch(TaskCategory::Other, notification.forget()));
  }
}

void Document::NotifyStyleSheetApplicableStateChanged() {
  mSSApplicableStateNotificationPending = false;
  nsCOMPtr<nsIObserverService> observerService =
      mozilla::services::GetObserverService();
  if (observerService) {
    observerService->NotifyObservers(
        ToSupports(this), "style-sheet-applicable-state-changed", nullptr);
  }
}

static StyleOrigin ConvertAdditionalSheetType(
    Document::additionalSheetType aType) {
  switch (aType) {
    case Document::eAgentSheet:
      return StyleOrigin::UserAgent;
    case Document::eUserSheet:
      return StyleOrigin::User;
    case Document::eAuthorSheet:
      return StyleOrigin::Author;
    default:
      MOZ_CRASH("Wrong sheet type");
  }
}

static int32_t FindSheet(const nsTArray<RefPtr<StyleSheet>>& aSheets,
                         nsIURI* aSheetURI) {
  for (int32_t i = aSheets.Length() - 1; i >= 0; i--) {
    bool bEqual;
    nsIURI* uri = aSheets[i]->GetSheetURI();

    if (uri && NS_SUCCEEDED(uri->Equals(aSheetURI, &bEqual)) && bEqual)
      return i;
  }

  return -1;
}

nsresult Document::LoadAdditionalStyleSheet(additionalSheetType aType,
                                            nsIURI* aSheetURI) {
  MOZ_ASSERT(aSheetURI, "null arg");

  // Checking if we have loaded this one already.
  if (FindSheet(mAdditionalSheets[aType], aSheetURI) >= 0)
    return NS_ERROR_INVALID_ARG;

  // Loading the sheet sync.
  RefPtr<css::Loader> loader = new css::Loader(GetDocGroup());

  css::SheetParsingMode parsingMode;
  switch (aType) {
    case Document::eAgentSheet:
      parsingMode = css::eAgentSheetFeatures;
      break;

    case Document::eUserSheet:
      parsingMode = css::eUserSheetFeatures;
      break;

    case Document::eAuthorSheet:
      parsingMode = css::eAuthorSheetFeatures;
      break;

    default:
      MOZ_CRASH("impossible value for aType");
  }

  RefPtr<StyleSheet> sheet;
  nsresult rv = loader->LoadSheetSync(aSheetURI, parsingMode, true, &sheet);
  NS_ENSURE_SUCCESS(rv, rv);

  sheet->SetAssociatedDocumentOrShadowRoot(
      this, StyleSheet::OwnedByDocumentOrShadowRoot);
  MOZ_ASSERT(sheet->IsApplicable());

  return AddAdditionalStyleSheet(aType, sheet);
}

nsresult Document::AddAdditionalStyleSheet(additionalSheetType aType,
                                           StyleSheet* aSheet) {
  if (mAdditionalSheets[aType].Contains(aSheet)) return NS_ERROR_INVALID_ARG;

  if (!aSheet->IsApplicable()) return NS_ERROR_INVALID_ARG;

  mAdditionalSheets[aType].AppendElement(aSheet);

  if (mStyleSetFilled) {
    mStyleSet->AppendStyleSheet(ConvertAdditionalSheetType(aType), aSheet);
    ApplicableStylesChanged();
  }

  // Passing false, so documet.styleSheets.length will not be affected by
  // these additional sheets.
  NotifyStyleSheetAdded(aSheet, false);
  return NS_OK;
}

void Document::RemoveAdditionalStyleSheet(additionalSheetType aType,
                                          nsIURI* aSheetURI) {
  MOZ_ASSERT(aSheetURI);

  nsTArray<RefPtr<StyleSheet>>& sheets = mAdditionalSheets[aType];

  int32_t i = FindSheet(mAdditionalSheets[aType], aSheetURI);
  if (i >= 0) {
    RefPtr<StyleSheet> sheetRef = sheets[i];
    sheets.RemoveElementAt(i);

    if (!mIsGoingAway) {
      MOZ_ASSERT(sheetRef->IsApplicable());
      if (mStyleSetFilled) {
        mStyleSet->RemoveStyleSheet(ConvertAdditionalSheetType(aType),
                                    sheetRef);
        ApplicableStylesChanged();
      }
    }

    // Passing false, so documet.styleSheets.length will not be affected by
    // these additional sheets.
    NotifyStyleSheetRemoved(sheetRef, false);
    sheetRef->ClearAssociatedDocumentOrShadowRoot();
  }
}

nsIGlobalObject* Document::GetScopeObject() const {
  nsCOMPtr<nsIGlobalObject> scope(do_QueryReferent(mScopeObject));
  return scope;
}

void Document::SetScopeObject(nsIGlobalObject* aGlobal) {
  mScopeObject = do_GetWeakReference(aGlobal);
  if (aGlobal) {
    mHasHadScriptHandlingObject = true;

    nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(aGlobal);
    if (window) {
      // We want to get the tabgroup unconditionally, such that we can make
      // certain that it is cached in the inner window early enough.
      mozilla::dom::TabGroup* tabgroup = window->TabGroup();
      // We should already have the principal, and now that we have been added
      // to a window, we should be able to join a DocGroup!
      nsAutoCString docGroupKey;
      nsresult rv =
          mozilla::dom::DocGroup::GetKey(NodePrincipal(), docGroupKey);
      if (mDocGroup) {
        if (NS_SUCCEEDED(rv)) {
          MOZ_RELEASE_ASSERT(mDocGroup->MatchesKey(docGroupKey));
        }
        MOZ_RELEASE_ASSERT(mDocGroup->GetTabGroup() == tabgroup);
      } else {
        mDocGroup = tabgroup->AddDocument(docGroupKey, this);
        MOZ_ASSERT(mDocGroup);
      }
    }
  }
}

static void CheckIfContainsEMEContent(nsISupports* aSupports,
                                      void* aContainsEME) {
  nsCOMPtr<nsIContent> content(do_QueryInterface(aSupports));
  if (auto mediaElem = HTMLMediaElement::FromNodeOrNull(content)) {
    bool* contains = static_cast<bool*>(aContainsEME);
    if (mediaElem->GetMediaKeys()) {
      *contains = true;
    }
  }
}

bool Document::ContainsEMEContent() {
  bool containsEME = false;
  EnumerateActivityObservers(CheckIfContainsEMEContent,
                             static_cast<void*>(&containsEME));
  return containsEME;
}

static void CheckIfContainsMSEContent(nsISupports* aSupports,
                                      void* aContainsMSE) {
  nsCOMPtr<nsIContent> content(do_QueryInterface(aSupports));
  if (auto mediaElem = HTMLMediaElement::FromNodeOrNull(content)) {
    bool* contains = static_cast<bool*>(aContainsMSE);
    RefPtr<MediaSource> ms = mediaElem->GetMozMediaSourceObject();
    if (ms) {
      *contains = true;
    }
  }
}

bool Document::ContainsMSEContent() {
  bool containsMSE = false;
  EnumerateActivityObservers(CheckIfContainsMSEContent,
                             static_cast<void*>(&containsMSE));
  return containsMSE;
}

static void NotifyActivityChanged(nsISupports* aSupports, void* aUnused) {
  nsCOMPtr<nsIContent> content(do_QueryInterface(aSupports));
  if (auto mediaElem = HTMLMediaElement::FromNodeOrNull(content)) {
    mediaElem->NotifyOwnerDocumentActivityChanged();
  }
  nsCOMPtr<nsIObjectLoadingContent> objectLoadingContent(
      do_QueryInterface(aSupports));
  if (objectLoadingContent) {
    nsObjectLoadingContent* olc =
        static_cast<nsObjectLoadingContent*>(objectLoadingContent.get());
    olc->NotifyOwnerDocumentActivityChanged();
  }
  nsCOMPtr<nsIDocumentActivity> objectDocumentActivity(
      do_QueryInterface(aSupports));
  if (objectDocumentActivity) {
    objectDocumentActivity->NotifyOwnerDocumentActivityChanged();
  } else {
    nsCOMPtr<nsIImageLoadingContent> imageLoadingContent(
        do_QueryInterface(aSupports));
    if (imageLoadingContent) {
      auto ilc = static_cast<nsImageLoadingContent*>(imageLoadingContent.get());
      ilc->NotifyOwnerDocumentActivityChanged();
    }
  }
}

bool Document::IsTopLevelWindowInactive() const {
  nsCOMPtr<nsIDocShellTreeItem> treeItem = GetDocShell();
  if (!treeItem) {
    return false;
  }

  nsCOMPtr<nsIDocShellTreeItem> rootItem;
  treeItem->GetRootTreeItem(getter_AddRefs(rootItem));
  if (!rootItem) {
    return false;
  }

  nsCOMPtr<nsPIDOMWindowOuter> domWindow = rootItem->GetWindow();
  return domWindow && !domWindow->IsActive();
}

void Document::SetContainer(nsDocShell* aContainer) {
  if (aContainer) {
    mDocumentContainer = aContainer;
  } else {
    mDocumentContainer = WeakPtr<nsDocShell>();
  }

  mInChromeDocShell =
      aContainer && aContainer->ItemType() == nsIDocShellTreeItem::typeChrome;

  EnumerateActivityObservers(NotifyActivityChanged, nullptr);

  // IsTopLevelWindowInactive depends on the docshell, so
  // update the cached value now that it's available.
  UpdateDocumentStates(NS_DOCUMENT_STATE_WINDOW_INACTIVE, false);
  if (!aContainer) {
    return;
  }

  BrowsingContext* context = aContainer->GetBrowsingContext();
  if (context && context->IsContent()) {
    if (!context->GetParent()) {
      SetIsTopLevelContentDocument(true);
    }
    SetIsContentDocument(true);
  }

  mAncestorPrincipals = aContainer->AncestorPrincipals();
  mAncestorOuterWindowIDs = aContainer->AncestorOuterWindowIDs();
}

nsISupports* Document::GetContainer() const {
  return static_cast<nsIDocShell*>(mDocumentContainer);
}

void Document::SetScriptGlobalObject(
    nsIScriptGlobalObject* aScriptGlobalObject) {
  MOZ_ASSERT(aScriptGlobalObject || !mAnimationController ||
                 mAnimationController->IsPausedByType(
                     SMILTimeContainer::PAUSE_PAGEHIDE |
                     SMILTimeContainer::PAUSE_BEGIN),
             "Clearing window pointer while animations are unpaused");

  if (mScriptGlobalObject && !aScriptGlobalObject) {
    // We're detaching from the window.  We need to grab a pointer to
    // our layout history state now.
    mLayoutHistoryState = GetLayoutHistoryState();

    // Also make sure to remove our onload blocker now if we haven't done it yet
    if (mOnloadBlockCount != 0) {
      nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
      if (loadGroup) {
        loadGroup->RemoveRequest(mOnloadBlocker, nullptr, NS_OK);
      }
    }

    ErrorResult error;
    if (GetController().isSome()) {
      imgLoader* loader = nsContentUtils::GetImgLoaderForDocument(this);
      if (loader) {
        loader->ClearCacheForControlledDocument(this);
      }

      // We may become controlled again if this document comes back out
      // of bfcache.  Clear our state to allow that to happen.  Only
      // clear this flag if we are actually controlled, though, so pages
      // that were force reloaded don't become controlled when they
      // come out of bfcache.
      mMaybeServiceWorkerControlled = false;
    }
  }

  // BlockOnload() might be called before mScriptGlobalObject is set.
  // We may need to add the blocker once mScriptGlobalObject is set.
  bool needOnloadBlocker = !mScriptGlobalObject && aScriptGlobalObject;

  mScriptGlobalObject = aScriptGlobalObject;

  if (needOnloadBlocker) {
    EnsureOnloadBlocker();
  }

  UpdateFrameRequestCallbackSchedulingState();

  if (aScriptGlobalObject) {
    // Go back to using the docshell for the layout history state
    mLayoutHistoryState = nullptr;
    SetScopeObject(aScriptGlobalObject);
    mHasHadDefaultView = true;

    if (mAllowDNSPrefetch) {
      nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
      if (docShell) {
#ifdef DEBUG
        nsCOMPtr<nsIWebNavigation> webNav =
            do_GetInterface(aScriptGlobalObject);
        NS_ASSERTION(SameCOMIdentity(webNav, docShell),
                     "Unexpected container or script global?");
#endif
        bool allowDNSPrefetch;
        docShell->GetAllowDNSPrefetch(&allowDNSPrefetch);
        mAllowDNSPrefetch = allowDNSPrefetch;
      }
    }

    // If we are set in a window that is already focused we should remember this
    // as the time the document gained focus.
    IgnoredErrorResult ignored;
    bool focused = HasFocus(ignored);
    if (focused) {
      SetLastFocusTime(TimeStamp::Now());
    }
  }

  // Remember the pointer to our window (or lack there of), to avoid
  // having to QI every time it's asked for.
  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(mScriptGlobalObject);
  mWindow = window;

  // Now that we know what our window is, we can flush the CSP errors to the
  // Web Console. We are flushing all messages that occured and were stored
  // in the queue prior to this point.
  nsCOMPtr<nsIContentSecurityPolicy> csp;
  NodePrincipal()->GetCsp(getter_AddRefs(csp));
  if (csp) {
    static_cast<nsCSPContext*>(csp.get())->flushConsoleMessages();
  }

  nsCOMPtr<nsIHttpChannelInternal> internalChannel =
      do_QueryInterface(GetChannel());
  if (internalChannel) {
    nsCOMArray<nsISecurityConsoleMessage> messages;
    DebugOnly<nsresult> rv = internalChannel->TakeAllSecurityMessages(messages);
    MOZ_ASSERT(NS_SUCCEEDED(rv));
    SendToConsole(messages);
  }

  // Set our visibility state, but do not fire the event.  This is correct
  // because either we're coming out of bfcache (in which case IsVisible() will
  // still test false at this point and no state change will happen) or we're
  // doing the initial document load and don't want to fire the event for this
  // change.
  dom::VisibilityState oldState = mVisibilityState;
  mVisibilityState = ComputeVisibilityState();
  // When the visibility is changed, notify it to observers.
  // Some observers need the notification, for example HTMLMediaElement uses
  // it to update internal media resource allocation.
  // When video is loaded via VideoDocument, HTMLMediaElement and MediaDecoder
  // creation are already done before Document::SetScriptGlobalObject() call.
  // MediaDecoder decides whether starting decoding is decided based on
  // document's visibility. When the MediaDecoder is created,
  // Document::SetScriptGlobalObject() is not yet called and document is
  // hidden state. Therefore the MediaDecoder decides that decoding is
  // not yet necessary. But soon after Document::SetScriptGlobalObject()
  // call, the document becomes not hidden. At the time, MediaDecoder needs
  // to know it and needs to start updating decoding.
  if (oldState != mVisibilityState) {
    EnumerateActivityObservers(NotifyActivityChanged, nullptr);
  }

  // The global in the template contents owner document should be the same.
  if (mTemplateContentsOwner && mTemplateContentsOwner != this) {
    mTemplateContentsOwner->SetScriptGlobalObject(aScriptGlobalObject);
  }

  if (!mMaybeServiceWorkerControlled && mDocumentContainer &&
      mScriptGlobalObject && GetChannel()) {
    // If we are shift-reloaded, don't associate with a ServiceWorker.
    if (mDocumentContainer->IsForceReloading()) {
      NS_WARNING("Page was shift reloaded, skipping ServiceWorker control");
      return;
    }

    mMaybeServiceWorkerControlled = true;
  }
}

nsIScriptGlobalObject* Document::GetScriptHandlingObjectInternal() const {
  MOZ_ASSERT(!mScriptGlobalObject,
             "Do not call this when mScriptGlobalObject is set!");
  if (mHasHadDefaultView) {
    return nullptr;
  }

  nsCOMPtr<nsIScriptGlobalObject> scriptHandlingObject =
      do_QueryReferent(mScopeObject);
  nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(scriptHandlingObject);
  if (win) {
    nsPIDOMWindowOuter* outer = win->GetOuterWindow();
    if (!outer || outer->GetCurrentInnerWindow() != win) {
      NS_WARNING("Wrong inner/outer window combination!");
      return nullptr;
    }
  }
  return scriptHandlingObject;
}
void Document::SetScriptHandlingObject(nsIScriptGlobalObject* aScriptObject) {
  NS_ASSERTION(!mScriptGlobalObject || mScriptGlobalObject == aScriptObject,
               "Wrong script object!");
  if (aScriptObject) {
    SetScopeObject(aScriptObject);
    mHasHadDefaultView = false;
  }
}

nsPIDOMWindowOuter* Document::GetWindowInternal() const {
  MOZ_ASSERT(!mWindow, "This should not be called when mWindow is not null!");
  // Let's use mScriptGlobalObject. Even if the document is already removed from
  // the docshell, the outer window might be still obtainable from the it.
  nsCOMPtr<nsPIDOMWindowOuter> win;
  if (mRemovedFromDocShell) {
    // The docshell returns the outer window we are done.
    nsCOMPtr<nsIDocShell> kungFuDeathGrip(mDocumentContainer);
    if (kungFuDeathGrip) {
      win = kungFuDeathGrip->GetWindow();
    }
  } else {
    if (nsCOMPtr<nsPIDOMWindowInner> inner =
            do_QueryInterface(mScriptGlobalObject)) {
      // mScriptGlobalObject is always the inner window, let's get the outer.
      win = inner->GetOuterWindow();
    }
  }

  return win;
}

bool Document::InternalAllowXULXBL() {
  if (nsContentUtils::AllowXULXBLForPrincipal(NodePrincipal())) {
    mAllowXULXBL = eTriTrue;
    return true;
  }

  mAllowXULXBL = eTriFalse;
  return false;
}

// Note: We don't hold a reference to the document observer; we assume
// that it has a live reference to the document.
void Document::AddObserver(nsIDocumentObserver* aObserver) {
  NS_ASSERTION(mObservers.IndexOf(aObserver) == nsTArray<int>::NoIndex,
               "Observer already in the list");
  mObservers.AppendElement(aObserver);
  AddMutationObserver(aObserver);
}

bool Document::RemoveObserver(nsIDocumentObserver* aObserver) {
  // If we're in the process of destroying the document (and we're
  // informing the observers of the destruction), don't remove the
  // observers from the list. This is not a big deal, since we
  // don't hold a live reference to the observers.
  if (!mInDestructor) {
    RemoveMutationObserver(aObserver);
    return mObservers.RemoveElement(aObserver);
  }

  return mObservers.Contains(aObserver);
}

void Document::MaybeEndOutermostXBLUpdate() {
  // Only call BindingManager()->EndOutermostUpdate() when
  // we're not in an update and it is safe to run scripts.
  if (mUpdateNestLevel == 0 && mInXBLUpdate) {
    if (nsContentUtils::IsSafeToRunScript()) {
      mInXBLUpdate = false;
      BindingManager()->EndOutermostUpdate();
    } else if (!mInDestructor) {
      if (!mMaybeEndOutermostXBLUpdateRunner) {
        mMaybeEndOutermostXBLUpdateRunner =
            NewRunnableMethod("Document::MaybeEndOutermostXBLUpdate", this,
                              &Document::MaybeEndOutermostXBLUpdate);
      }
      nsContentUtils::AddScriptRunner(mMaybeEndOutermostXBLUpdateRunner);
    }
  }
}

void Document::BeginUpdate() {
  // If the document is going away, then it's probably okay to do things to it
  // in the wrong DocGroup. We're unlikely to run JS or do anything else
  // observable at this point. We reach this point when cycle collecting a
  // <link> element and the unlink code removes a style sheet.
  //
  // TODO(emilio): Style updates are gone, can this happen now?
  if (mDocGroup && !mIsGoingAway && !mInUnlinkOrDeletion &&
      !mIgnoreDocGroupMismatches) {
    mDocGroup->ValidateAccess();
  }

  if (mUpdateNestLevel == 0 && !mInXBLUpdate) {
    mInXBLUpdate = true;
    BindingManager()->BeginOutermostUpdate();
  }

  ++mUpdateNestLevel;
  nsContentUtils::AddScriptBlocker();
  NS_DOCUMENT_NOTIFY_OBSERVERS(BeginUpdate, (this));
}

void Document::EndUpdate() {
  NS_DOCUMENT_NOTIFY_OBSERVERS(EndUpdate, (this));

  nsContentUtils::RemoveScriptBlocker();

  --mUpdateNestLevel;

  // This set of updates may have created XBL bindings.  Let the
  // binding manager know we're done.
  MaybeEndOutermostXBLUpdate();

  MaybeInitializeFinalizeFrameLoaders();
  if (mXULBroadcastManager) {
    mXULBroadcastManager->MaybeBroadcast();
  }
}

void Document::BeginLoad() {
  MOZ_ASSERT(!mDidCallBeginLoad);
  mDidCallBeginLoad = true;

  // Block onload here to prevent having to deal with blocking and
  // unblocking it while we know the document is loading.
  BlockOnload();
  mDidFireDOMContentLoaded = false;
  BlockDOMContentLoaded();

  if (mScriptLoader) {
    mScriptLoader->BeginDeferringScripts();
  }

  NS_DOCUMENT_NOTIFY_OBSERVERS(BeginLoad, (this));
}

void Document::MozSetImageElement(const nsAString& aImageElementId,
                                  Element* aElement) {
  if (aImageElementId.IsEmpty()) return;

  // Hold a script blocker while calling SetImageElement since that can call
  // out to id-observers
  nsAutoScriptBlocker scriptBlocker;

  IdentifierMapEntry* entry = mIdentifierMap.PutEntry(aImageElementId);
  if (entry) {
    entry->SetImageElement(aElement);
    if (entry->IsEmpty()) {
      mIdentifierMap.RemoveEntry(entry);
    }
  }
}

void Document::DispatchContentLoadedEvents() {
  // If you add early returns from this method, make sure you're
  // calling UnblockOnload properly.

  // Unpin references to preloaded images
  mPreloadingImages.Clear();

  // DOM manipulation after content loaded should not care if the element
  // came from the preloader.
  mPreloadedPreconnects.Clear();

  if (mTiming) {
    mTiming->NotifyDOMContentLoadedStart(Document::GetDocumentURI());
  }

  // Dispatch observer notification to notify observers document is interactive.
  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
  if (os) {
    nsIPrincipal* principal = NodePrincipal();
    os->NotifyObservers(ToSupports(this),
                        nsContentUtils::IsSystemPrincipal(principal)
                            ? "chrome-document-interactive"
                            : "content-document-interactive",
                        nullptr);
  }

  // Fire a DOM event notifying listeners that this document has been
  // loaded (excluding images and other loads initiated by this
  // document).
  nsContentUtils::DispatchTrustedEvent(this, ToSupports(this),
                                       NS_LITERAL_STRING("DOMContentLoaded"),
                                       CanBubble::eYes, Cancelable::eNo);

  if (auto* const window = GetInnerWindow()) {
    const RefPtr<ServiceWorkerContainer> serviceWorker =
        window->Navigator()->ServiceWorker();

    // This could cause queued messages from a service worker to get
    // dispatched on serviceWorker.
    serviceWorker->StartMessages();
  }

  if (MayStartLayout()) {
    MaybeResolveReadyForIdle();
  }

  RefPtr<TimelineConsumers> timelines = TimelineConsumers::Get();
  nsIDocShell* docShell = this->GetDocShell();

  if (timelines && timelines->HasConsumer(docShell)) {
    timelines->AddMarkerForDocShell(
        docShell,
        MakeUnique<DocLoadingTimelineMarker>("document::DOMContentLoaded"));
  }

  if (mTiming) {
    mTiming->NotifyDOMContentLoadedEnd(Document::GetDocumentURI());
  }

  // If this document is a [i]frame, fire a DOMFrameContentLoaded
  // event on all parent documents notifying that the HTML (excluding
  // other external files such as images and stylesheets) in a frame
  // has finished loading.

  // target_frame is the [i]frame element that will be used as the
  // target for the event. It's the [i]frame whose content is done
  // loading.
  nsCOMPtr<EventTarget> target_frame;

  if (mParentDocument) {
    target_frame = mParentDocument->FindContentForSubDocument(this);
  }

  if (target_frame) {
    nsCOMPtr<Document> parent = mParentDocument;
    do {
      RefPtr<Event> event;
      if (parent) {
        IgnoredErrorResult ignored;
        event = parent->CreateEvent(NS_LITERAL_STRING("Events"),
                                    CallerType::System, ignored);
      }

      if (event) {
        event->InitEvent(NS_LITERAL_STRING("DOMFrameContentLoaded"), true,
                         true);

        event->SetTarget(target_frame);
        event->SetTrusted(true);

        // To dispatch this event we must manually call
        // EventDispatcher::Dispatch() on the ancestor document since the
        // target is not in the same document, so the event would never reach
        // the ancestor document if we used the normal event
        // dispatching code.

        WidgetEvent* innerEvent = event->WidgetEventPtr();
        if (innerEvent) {
          nsEventStatus status = nsEventStatus_eIgnore;

          if (RefPtr<nsPresContext> context = parent->GetPresContext()) {
            EventDispatcher::Dispatch(ToSupports(parent), context, innerEvent,
                                      event, &status);
          }
        }
      }

      parent = parent->GetParentDocument();
    } while (parent);
  }

  // If the document has a manifest attribute, fire a MozApplicationManifest
  // event.
  Element* root = GetRootElement();
  if (root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::manifest)) {
    nsContentUtils::DispatchChromeEvent(
        this, ToSupports(this), NS_LITERAL_STRING("MozApplicationManifest"),
        CanBubble::eYes, Cancelable::eYes);
  }

  nsPIDOMWindowInner* inner = GetInnerWindow();
  if (inner) {
    inner->NoteDOMContentLoaded();
  }

  // TODO
  if (mMaybeServiceWorkerControlled) {
    using mozilla::dom::ServiceWorkerManager;
    RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
    if (swm) {
      Maybe<ClientInfo> clientInfo = GetClientInfo();
      if (clientInfo.isSome()) {
        swm->MaybeCheckNavigationUpdate(clientInfo.ref());
      }
    }
  }

  UnblockOnload(true);
}

#if defined(DEBUG) && !defined(ANDROID)
// We want to get to a point where all about: pages ship with a CSP. This
// assertion ensures that we can not deploy new about: pages without a CSP.
// Initially we will whitelist legacy about: pages which not yet have a CSP
// attached, but ultimately that whitelist should disappear.
// Please note that any about: page should not use inline JS or inline CSS,
// and instead should load JS and CSS from an external file (*.js, *.css)
// which allows us to apply a strong CSP omitting 'unsafe-inline'. Ideally,
// the CSP allows precisely the resources that need to be loaded; but it
// should at least be as strong as:
// <meta http-equiv="Content-Security-Policy" content="default-src chrome:"/>
static void AssertAboutPageHasCSP(nsIURI* aDocumentURI,
                                  nsIPrincipal* aPrincipal) {
  // Check if we are loading an about: URI at all
  bool isAboutURI =
      (NS_SUCCEEDED(aDocumentURI->SchemeIs("about", &isAboutURI)) &&
       isAboutURI);

  if (!isAboutURI ||
      Preferences::GetBool("csp.skip_about_page_has_csp_assert")) {
    return;
  }

  // Potentially init the legacy whitelist of about URIs without a CSP.
  static StaticAutoPtr<nsTArray<nsCString>> sLegacyAboutPagesWithNoCSP;
  if (!sLegacyAboutPagesWithNoCSP ||
      Preferences::GetBool("csp.overrule_about_uris_without_csp_whitelist")) {
    sLegacyAboutPagesWithNoCSP = new nsTArray<nsCString>();
    nsAutoCString legacyAboutPages;
    Preferences::GetCString("csp.about_uris_without_csp", legacyAboutPages);
    for (const nsACString& hostString : legacyAboutPages.Split(',')) {
      // please note that for the actual whitelist we only store the path of
      // about: URI. Let's reassemble the full about URI here so we don't
      // have to remove query arguments later.
      nsCString aboutURI;
      aboutURI.AppendLiteral("about:");
      aboutURI.Append(hostString);
      sLegacyAboutPagesWithNoCSP->AppendElement(aboutURI);
    }
    ClearOnShutdown(&sLegacyAboutPagesWithNoCSP);
  }

  // Check if the about URI is whitelisted
  nsAutoCString aboutSpec;
  aDocumentURI->GetSpec(aboutSpec);
  ToLowerCase(aboutSpec);
  for (auto& legacyPageEntry : *sLegacyAboutPagesWithNoCSP) {
    // please note that we perform a substring match here on purpose,
    // so we don't have to deal and parse out all the query arguments
    // the various about pages rely on.
    if (aboutSpec.Find(legacyPageEntry) == 0) {
      return;
    }
  }

  nsCOMPtr<nsIContentSecurityPolicy> csp;
  aPrincipal->GetCsp(getter_AddRefs(csp));
  bool foundDefaultSrc = false;
  if (csp) {
    uint32_t policyCount = 0;
    csp->GetPolicyCount(&policyCount);
    nsAutoString parsedPolicyStr;
    for (uint32_t i = 0; i < policyCount; ++i) {
      csp->GetPolicyString(i, parsedPolicyStr);
      if (parsedPolicyStr.Find("default-src") >= 0) {
        foundDefaultSrc = true;
        break;
      }
    }
  }
  if (Preferences::GetBool("csp.overrule_about_uris_without_csp_whitelist")) {
    NS_ASSERTION(foundDefaultSrc, "about: page must have a CSP");
    return;
  }
  MOZ_ASSERT(foundDefaultSrc,
             "about: page must contain a CSP including default-src");
}
#endif

void Document::EndLoad() {
#if defined(DEBUG) && !defined(ANDROID)
  // only assert if nothing stopped the load on purpose
  // TODO: we probably also want to check XUL documents here too
  if (!mParserAborted && !IsXULDocument()) {
    AssertAboutPageHasCSP(mDocumentURI, NodePrincipal());
  }
#endif

  // EndLoad may have been called without a matching call to BeginLoad, in the
  // case of a failed parse (for example, due to timeout). In such a case, we
  // still want to execute part of this code to do appropriate cleanup, but we
  // gate part of it because it is intended to match 1-for-1 with calls to
  // BeginLoad. We have an explicit flag bit for this purpose, since it's
  // complicated and error prone to derive this condition from other related
  // flags that can be manipulated outside of a BeginLoad/EndLoad pair.

  // Part 1: Code that always executes to cleanup end of parsing, whether
  // that parsing was successful or not.

  // Drop the ref to our parser, if any, but keep hold of the sink so that we
  // can flush it from FlushPendingNotifications as needed.  We might have to
  // do that to get a StartLayout() to happen.
  if (mParser) {
    mWeakSink = do_GetWeakReference(mParser->GetContentSink());
    mParser = nullptr;
  }

  NS_DOCUMENT_NOTIFY_OBSERVERS(EndLoad, (this));

  // Part 2: Code that only executes when this EndLoad matches a BeginLoad.

  if (!mDidCallBeginLoad) {
    return;
  }
  mDidCallBeginLoad = false;

  UnblockDOMContentLoaded();
}

void Document::UnblockDOMContentLoaded() {
  MOZ_ASSERT(mBlockDOMContentLoaded);
  if (--mBlockDOMContentLoaded != 0 || mDidFireDOMContentLoaded) {
    return;
  }

  MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug,
          ("DOCUMENT %p UnblockDOMContentLoaded", this));

  mDidFireDOMContentLoaded = true;
  if (PresShell* presShell = GetPresShell()) {
    presShell->GetRefreshDriver()->NotifyDOMContentLoaded();
  }

  MOZ_ASSERT(mReadyState == READYSTATE_INTERACTIVE);
  if (!mSynchronousDOMContentLoaded) {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    nsCOMPtr<nsIRunnable> ev =
        NewRunnableMethod("Document::DispatchContentLoadedEvents", this,
                          &Document::DispatchContentLoadedEvents);
    Dispatch(TaskCategory::Other, ev.forget());
  } else {
    DispatchContentLoadedEvents();
  }
}

void Document::ContentStateChanged(nsIContent* aContent,
                                   EventStates aStateMask) {
  MOZ_ASSERT(!nsContentUtils::IsSafeToRunScript(),
             "Someone forgot a scriptblocker");
  NS_DOCUMENT_NOTIFY_OBSERVERS(ContentStateChanged,
                               (this, aContent, aStateMask));
}

void Document::StyleRuleChanged(StyleSheet* aSheet, css::Rule* aStyleRule) {
  ApplicableStylesChanged();

  if (!StyleSheetChangeEventsEnabled()) {
    return;
  }

  DO_STYLESHEET_NOTIFICATION(StyleRuleChangeEvent, "StyleRuleChanged", mRule,
                             aStyleRule);
}

void Document::StyleRuleAdded(StyleSheet* aSheet, css::Rule* aStyleRule) {
  ApplicableStylesChanged();

  if (!StyleSheetChangeEventsEnabled()) {
    return;
  }

  DO_STYLESHEET_NOTIFICATION(StyleRuleChangeEvent, "StyleRuleAdded", mRule,
                             aStyleRule);
}

void Document::StyleRuleRemoved(StyleSheet* aSheet, css::Rule* aStyleRule) {
  ApplicableStylesChanged();

  if (!StyleSheetChangeEventsEnabled()) {
    return;
  }

  DO_STYLESHEET_NOTIFICATION(StyleRuleChangeEvent, "StyleRuleRemoved", mRule,
                             aStyleRule);
}

#undef DO_STYLESHEET_NOTIFICATION

static Element* GetCustomContentContainer(PresShell* aPresShell) {
  if (!aPresShell || !aPresShell->GetCanvasFrame()) {
    return nullptr;
  }

  return aPresShell->GetCanvasFrame()->GetCustomContentContainer();
}

static void InsertAnonContentIntoCanvas(AnonymousContent& aAnonContent,
                                        PresShell* aPresShell) {
  Element* container = GetCustomContentContainer(aPresShell);
  if (!container) {
    return;
  }

  nsresult rv = container->AppendChildTo(&aAnonContent.ContentNode(), true);
  if (NS_FAILED(rv)) {
    return;
  }

  aPresShell->GetCanvasFrame()->ShowCustomContentContainer();
}

already_AddRefed<AnonymousContent> Document::InsertAnonymousContent(
    Element& aElement, ErrorResult& aRv) {
  nsAutoScriptBlocker scriptBlocker;

  // Clone the node to avoid returning a direct reference.
  nsCOMPtr<nsINode> clone = aElement.CloneNode(true, aRv);
  if (aRv.Failed()) {
    return nullptr;
  }

  auto anonContent =
      MakeRefPtr<AnonymousContent>(clone.forget().downcast<Element>());
  mAnonymousContents.AppendElement(anonContent);

  InsertAnonContentIntoCanvas(*anonContent, GetPresShell());

  return anonContent.forget();
}

static void RemoveAnonContentFromCanvas(AnonymousContent& aAnonContent,
                                        PresShell* aPresShell) {
  RefPtr<Element> container = GetCustomContentContainer(aPresShell);
  if (!container) {
    return;
  }
  container->RemoveChild(aAnonContent.ContentNode(), IgnoreErrors());
}

void Document::RemoveAnonymousContent(AnonymousContent& aContent,
                                      ErrorResult& aRv) {
  nsAutoScriptBlocker scriptBlocker;

  auto index = mAnonymousContents.IndexOf(&aContent);
  if (index == mAnonymousContents.NoIndex) {
    return;
  }

  mAnonymousContents.RemoveElementAt(index);
  RemoveAnonContentFromCanvas(aContent, GetPresShell());

  if (mAnonymousContents.IsEmpty() &&
      GetCustomContentContainer(GetPresShell())) {
    GetPresShell()->GetCanvasFrame()->HideCustomContentContainer();
  }
}

Element* Document::GetAnonRootIfInAnonymousContentContainer(
    nsINode* aNode) const {
  if (!aNode->IsInNativeAnonymousSubtree()) {
    return nullptr;
  }

  PresShell* presShell = GetPresShell();
  if (!presShell || !presShell->GetCanvasFrame()) {
    return nullptr;
  }

  nsAutoScriptBlocker scriptBlocker;
  nsCOMPtr<Element> customContainer =
      presShell->GetCanvasFrame()->GetCustomContentContainer();
  if (!customContainer) {
    return nullptr;
  }

  // An arbitrary number of elements can be inserted as children of the custom
  // container frame.  We want the one that was added that contains aNode, so
  // we need to keep track of the last child separately using |child| here.
  nsINode* child = aNode;
  nsINode* parent = aNode->GetParentNode();
  while (parent && parent->IsInNativeAnonymousSubtree()) {
    if (parent == customContainer) {
      return Element::FromNode(child);
    }
    child = parent;
    parent = child->GetParentNode();
  }
  return nullptr;
}

Maybe<ClientInfo> Document::GetClientInfo() const {
  nsPIDOMWindowInner* inner = GetInnerWindow();
  if (inner) {
    return inner->GetClientInfo();
  }
  return Maybe<ClientInfo>();
}

Maybe<ClientState> Document::GetClientState() const {
  nsPIDOMWindowInner* inner = GetInnerWindow();
  if (inner) {
    return inner->GetClientState();
  }
  return Maybe<ClientState>();
}

Maybe<ServiceWorkerDescriptor> Document::GetController() const {
  nsPIDOMWindowInner* inner = GetInnerWindow();
  if (inner) {
    return inner->GetController();
  }
  return Maybe<ServiceWorkerDescriptor>();
}

//
// Document interface
//
DocumentType* Document::GetDoctype() const {
  for (nsIContent* child = GetFirstChild(); child;
       child = child->GetNextSibling()) {
    if (child->NodeType() == DOCUMENT_TYPE_NODE) {
      return static_cast<DocumentType*>(child);
    }
  }
  return nullptr;
}

DOMImplementation* Document::GetImplementation(ErrorResult& rv) {
  if (!mDOMImplementation) {
    nsCOMPtr<nsIURI> uri;
    NS_NewURI(getter_AddRefs(uri), "about:blank");
    if (!uri) {
      rv.Throw(NS_ERROR_OUT_OF_MEMORY);
      return nullptr;
    }
    bool hasHadScriptObject = true;
    nsIScriptGlobalObject* scriptObject =
        GetScriptHandlingObject(hasHadScriptObject);
    if (!scriptObject && hasHadScriptObject) {
      rv.Throw(NS_ERROR_UNEXPECTED);
      return nullptr;
    }
    mDOMImplementation = new DOMImplementation(
        this, scriptObject ? scriptObject : GetScopeObject(), uri, uri);
  }

  return mDOMImplementation;
}

bool IsLowercaseASCII(const nsAString& aValue) {
  int32_t len = aValue.Length();
  for (int32_t i = 0; i < len; ++i) {
    char16_t c = aValue[i];
    if (!(0x0061 <= (c) && ((c) <= 0x007a))) {
      return false;
    }
  }
  return true;
}

// We only support pseudo-elements with two colons in this function.
static PseudoStyleType GetPseudoElementType(const nsString& aString,
                                            ErrorResult& aRv) {
  MOZ_ASSERT(!aString.IsEmpty(),
             "GetPseudoElementType aString should be non-null");
  if (aString.Length() <= 2 || aString[0] != ':' || aString[1] != ':') {
    aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
    return PseudoStyleType::NotPseudo;
  }
  RefPtr<nsAtom> pseudo = NS_Atomize(Substring(aString, 1));
  return nsCSSPseudoElements::GetPseudoType(pseudo,
                                            CSSEnabledState::InUASheets);
}

already_AddRefed<Element> Document::CreateElement(
    const nsAString& aTagName, const ElementCreationOptionsOrString& aOptions,
    ErrorResult& rv) {
  rv = nsContentUtils::CheckQName(aTagName, false);
  if (rv.Failed()) {
    return nullptr;
  }

  bool needsLowercase = IsHTMLDocument() && !IsLowercaseASCII(aTagName);
  nsAutoString lcTagName;
  if (needsLowercase) {
    nsContentUtils::ASCIIToLower(aTagName, lcTagName);
  }

  const nsString* is = nullptr;
  PseudoStyleType pseudoType = PseudoStyleType::NotPseudo;
  if (aOptions.IsElementCreationOptions()) {
    const ElementCreationOptions& options =
        aOptions.GetAsElementCreationOptions();

    if (options.mIs.WasPassed()) {
      is = &options.mIs.Value();
    }

    // Check 'pseudo' and throw an exception if it's not one allowed
    // with CSS_PSEUDO_ELEMENT_IS_JS_CREATED_NAC.
    if (options.mPseudo.WasPassed()) {
      pseudoType = GetPseudoElementType(options.mPseudo.Value(), rv);
      if (rv.Failed() || pseudoType == PseudoStyleType::NotPseudo ||
          !nsCSSPseudoElements::PseudoElementIsJSCreatedNAC(pseudoType)) {
        rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
        return nullptr;
      }
    }
  }

  RefPtr<Element> elem = CreateElem(needsLowercase ? lcTagName : aTagName,
                                    nullptr, mDefaultElementType, is);

  if (pseudoType != PseudoStyleType::NotPseudo) {
    elem->SetPseudoElementType(pseudoType);
  }

  return elem.forget();
}

already_AddRefed<Element> Document::CreateElementNS(
    const nsAString& aNamespaceURI, const nsAString& aQualifiedName,
    const ElementCreationOptionsOrString& aOptions, ErrorResult& rv) {
  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  rv = nsContentUtils::GetNodeInfoFromQName(aNamespaceURI, aQualifiedName,
                                            mNodeInfoManager, ELEMENT_NODE,
                                            getter_AddRefs(nodeInfo));
  if (rv.Failed()) {
    return nullptr;
  }

  const nsString* is = nullptr;
  if (aOptions.IsElementCreationOptions()) {
    const ElementCreationOptions& options =
        aOptions.GetAsElementCreationOptions();
    if (options.mIs.WasPassed()) {
      is = &options.mIs.Value();
    }
  }

  nsCOMPtr<Element> element;
  rv = NS_NewElement(getter_AddRefs(element), nodeInfo.forget(),
                     NOT_FROM_PARSER, is);
  if (rv.Failed()) {
    return nullptr;
  }

  return element.forget();
}

already_AddRefed<Element> Document::CreateXULElement(
    const nsAString& aTagName, const ElementCreationOptionsOrString& aOptions,
    ErrorResult& aRv) {
  aRv = nsContentUtils::CheckQName(aTagName, false);
  if (aRv.Failed()) {
    return nullptr;
  }

  const nsString* is = nullptr;
  if (aOptions.IsElementCreationOptions()) {
    const ElementCreationOptions& options =
        aOptions.GetAsElementCreationOptions();
    if (options.mIs.WasPassed()) {
      is = &options.mIs.Value();
    }
  }

  RefPtr<Element> elem = CreateElem(aTagName, nullptr, kNameSpaceID_XUL, is);
  if (!elem) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }
  return elem.forget();
}

already_AddRefed<nsTextNode> Document::CreateEmptyTextNode() const {
  RefPtr<nsTextNode> text = new nsTextNode(mNodeInfoManager);
  return text.forget();
}

already_AddRefed<nsTextNode> Document::CreateTextNode(
    const nsAString& aData) const {
  RefPtr<nsTextNode> text = new nsTextNode(mNodeInfoManager);
  // Don't notify; this node is still being created.
  text->SetText(aData, false);
  return text.forget();
}

already_AddRefed<DocumentFragment> Document::CreateDocumentFragment() const {
  RefPtr<DocumentFragment> frag = new DocumentFragment(mNodeInfoManager);
  return frag.forget();
}

// Unfortunately, bareword "Comment" is ambiguous with some Mac system headers.
already_AddRefed<dom::Comment> Document::CreateComment(
    const nsAString& aData) const {
  RefPtr<dom::Comment> comment = new dom::Comment(mNodeInfoManager);

  // Don't notify; this node is still being created.
  comment->SetText(aData, false);
  return comment.forget();
}

already_AddRefed<CDATASection> Document::CreateCDATASection(
    const nsAString& aData, ErrorResult& rv) {
  if (IsHTMLDocument()) {
    rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
    return nullptr;
  }

  if (FindInReadable(NS_LITERAL_STRING("]]>"), aData)) {
    rv.Throw(NS_ERROR_DOM_INVALID_CHARACTER_ERR);
    return nullptr;
  }

  RefPtr<CDATASection> cdata = new CDATASection(mNodeInfoManager);

  // Don't notify; this node is still being created.
  cdata->SetText(aData, false);

  return cdata.forget();
}

already_AddRefed<ProcessingInstruction> Document::CreateProcessingInstruction(
    const nsAString& aTarget, const nsAString& aData, ErrorResult& rv) const {
  nsresult res = nsContentUtils::CheckQName(aTarget, false);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  if (FindInReadable(NS_LITERAL_STRING("?>"), aData)) {
    rv.Throw(NS_ERROR_DOM_INVALID_CHARACTER_ERR);
    return nullptr;
  }

  RefPtr<ProcessingInstruction> pi =
      NS_NewXMLProcessingInstruction(mNodeInfoManager, aTarget, aData);

  return pi.forget();
}

already_AddRefed<Attr> Document::CreateAttribute(const nsAString& aName,
                                                 ErrorResult& rv) {
  if (!mNodeInfoManager) {
    rv.Throw(NS_ERROR_NOT_INITIALIZED);
    return nullptr;
  }

  nsresult res = nsContentUtils::CheckQName(aName, false);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  nsAutoString name;
  if (IsHTMLDocument()) {
    nsContentUtils::ASCIIToLower(aName, name);
  } else {
    name = aName;
  }

  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  res = mNodeInfoManager->GetNodeInfo(name, nullptr, kNameSpaceID_None,
                                      ATTRIBUTE_NODE, getter_AddRefs(nodeInfo));
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  RefPtr<Attr> attribute = new Attr(nullptr, nodeInfo.forget(), EmptyString());
  return attribute.forget();
}

already_AddRefed<Attr> Document::CreateAttributeNS(
    const nsAString& aNamespaceURI, const nsAString& aQualifiedName,
    ErrorResult& rv) {
  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  rv = nsContentUtils::GetNodeInfoFromQName(aNamespaceURI, aQualifiedName,
                                            mNodeInfoManager, ATTRIBUTE_NODE,
                                            getter_AddRefs(nodeInfo));
  if (rv.Failed()) {
    return nullptr;
  }

  RefPtr<Attr> attribute = new Attr(nullptr, nodeInfo.forget(), EmptyString());
  return attribute.forget();
}

void Document::ResolveScheduledSVGPresAttrs() {
  for (auto iter = mLazySVGPresElements.Iter(); !iter.Done(); iter.Next()) {
    SVGElement* svg = iter.Get()->GetKey();
    svg->UpdateContentDeclarationBlock();
  }
  mLazySVGPresElements.Clear();
}

already_AddRefed<nsSimpleContentList> Document::BlockedNodesByClassifier()
    const {
  RefPtr<nsSimpleContentList> list = new nsSimpleContentList(nullptr);

  nsTArray<nsWeakPtr> blockedNodes;
  blockedNodes = mBlockedNodesByClassifier;

  for (unsigned long i = 0; i < blockedNodes.Length(); i++) {
    nsWeakPtr weakNode = blockedNodes[i];
    nsCOMPtr<nsIContent> node = do_QueryReferent(weakNode);
    // Consider only nodes to which we have managed to get strong references.
    // Coping with nullptrs since it's expected for nodes to disappear when
    // nobody else is referring to them.
    if (node) {
      list->AppendElement(node);
    }
  }

  return list.forget();
}

void Document::GetSelectedStyleSheetSet(nsAString& aSheetSet) {
  aSheetSet.Truncate();

  // Look through our sheets, find the selected set title
  size_t count = SheetCount();
  nsAutoString title;
  for (size_t index = 0; index < count; index++) {
    StyleSheet* sheet = SheetAt(index);
    NS_ASSERTION(sheet, "Null sheet in sheet list!");

    if (sheet->Disabled()) {
      // Disabled sheets don't affect the currently selected set
      continue;
    }

    sheet->GetTitle(title);

    if (aSheetSet.IsEmpty()) {
      aSheetSet = title;
    } else if (!title.IsEmpty() && !aSheetSet.Equals(title)) {
      // Sheets from multiple sets enabled; return null string, per spec.
      SetDOMStringToNull(aSheetSet);
      return;
    }
  }
}

void Document::SetSelectedStyleSheetSet(const nsAString& aSheetSet) {
  if (DOMStringIsNull(aSheetSet)) {
    return;
  }

  // Must update mLastStyleSheetSet before doing anything else with stylesheets
  // or CSSLoaders.
  mLastStyleSheetSet = aSheetSet;
  EnableStyleSheetsForSetInternal(aSheetSet, true);
}

void Document::SetPreferredStyleSheetSet(const nsAString& aSheetSet) {
  mPreferredStyleSheetSet = aSheetSet;
  // Only mess with our stylesheets if we don't have a lastStyleSheetSet, per
  // spec.
  if (DOMStringIsNull(mLastStyleSheetSet)) {
    // Calling EnableStyleSheetsForSetInternal, not SetSelectedStyleSheetSet,
    // per spec.  The idea here is that we're changing our preferred set and
    // that shouldn't change the value of lastStyleSheetSet.  Also, we're
    // using the Internal version so we can update the CSSLoader and not have
    // to worry about null strings.
    EnableStyleSheetsForSetInternal(aSheetSet, true);
  }
}

DOMStringList* Document::StyleSheetSets() {
  if (!mStyleSheetSetList) {
    mStyleSheetSetList = new DOMStyleSheetSetList(this);
  }
  return mStyleSheetSetList;
}

void Document::EnableStyleSheetsForSet(const nsAString& aSheetSet) {
  // Per spec, passing in null is a no-op.
  if (!DOMStringIsNull(aSheetSet)) {
    // Note: must make sure to not change the CSSLoader's preferred sheet --
    // that value should be equal to either our lastStyleSheetSet (if that's
    // non-null) or to our preferredStyleSheetSet.  And this method doesn't
    // change either of those.
    EnableStyleSheetsForSetInternal(aSheetSet, false);
  }
}

void Document::EnableStyleSheetsForSetInternal(const nsAString& aSheetSet,
                                               bool aUpdateCSSLoader) {
  size_t count = SheetCount();
  nsAutoString title;
  for (size_t index = 0; index < count; index++) {
    StyleSheet* sheet = SheetAt(index);
    NS_ASSERTION(sheet, "Null sheet in sheet list!");

    sheet->GetTitle(title);
    if (!title.IsEmpty()) {
      sheet->SetEnabled(title.Equals(aSheetSet));
    }
  }
  if (aUpdateCSSLoader) {
    CSSLoader()->DocumentStyleSheetSetChanged();
  }
  if (mStyleSet->StyleSheetsHaveChanged()) {
    ApplicableStylesChanged();
  }
}

void Document::GetCharacterSet(nsAString& aCharacterSet) const {
  nsAutoCString charset;
  GetDocumentCharacterSet()->Name(charset);
  CopyASCIItoUTF16(charset, aCharacterSet);
}

already_AddRefed<nsINode> Document::ImportNode(nsINode& aNode, bool aDeep,
                                               ErrorResult& rv) const {
  nsINode* imported = &aNode;

  switch (imported->NodeType()) {
    case DOCUMENT_NODE: {
      break;
    }
    case DOCUMENT_FRAGMENT_NODE:
    case ATTRIBUTE_NODE:
    case ELEMENT_NODE:
    case PROCESSING_INSTRUCTION_NODE:
    case TEXT_NODE:
    case CDATA_SECTION_NODE:
    case COMMENT_NODE:
    case DOCUMENT_TYPE_NODE: {
      return nsNodeUtils::Clone(imported, aDeep, mNodeInfoManager, nullptr, rv);
    }
    default: {
      NS_WARNING("Don't know how to clone this nodetype for importNode.");
    }
  }

  rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
  return nullptr;
}

void Document::LoadBindingDocument(const nsAString& aURI,
                                   nsIPrincipal& aSubjectPrincipal,
                                   ErrorResult& rv) {
  nsCOMPtr<nsIURI> uri;
  rv = NS_NewURI(getter_AddRefs(uri), aURI, mCharacterSet, GetDocBaseURI());
  if (rv.Failed()) {
    return;
  }

  BindingManager()->LoadBindingDocument(this, uri, &aSubjectPrincipal);
}

Element* Document::GetBindingParent(nsINode& aNode) {
  nsCOMPtr<nsIContent> content(do_QueryInterface(&aNode));
  if (!content) return nullptr;

  nsIContent* bindingParent = content->GetBindingParent();
  return bindingParent ? bindingParent->AsElement() : nullptr;
}

static Element* GetElementByAttribute(Element* aElement, nsAtom* aAttrName,
                                      const nsAString& aAttrValue,
                                      bool aUniversalMatch) {
  if (aUniversalMatch ? aElement->HasAttr(kNameSpaceID_None, aAttrName)
                      : aElement->AttrValueIs(kNameSpaceID_None, aAttrName,
                                              aAttrValue, eCaseMatters)) {
    return aElement;
  }

  for (nsIContent* child = aElement->GetFirstChild(); child;
       child = child->GetNextSibling()) {
    if (!child->IsElement()) {
      continue;
    }

    Element* matchedElement = GetElementByAttribute(
        child->AsElement(), aAttrName, aAttrValue, aUniversalMatch);
    if (matchedElement) return matchedElement;
  }

  return nullptr;
}

Element* Document::GetAnonymousElementByAttribute(
    nsIContent* aElement, nsAtom* aAttrName,
    const nsAString& aAttrValue) const {
  nsINodeList* nodeList = BindingManager()->GetAnonymousNodesFor(aElement);
  if (!nodeList) return nullptr;

  uint32_t length = nodeList->Length();

  bool universalMatch = aAttrValue.EqualsLiteral("*");

  for (uint32_t i = 0; i < length; ++i) {
    Element* current = Element::FromNode(nodeList->Item(i));
    if (!current) {
      continue;
    }

    Element* matchedElm =
        GetElementByAttribute(current, aAttrName, aAttrValue, universalMatch);
    if (matchedElm) return matchedElm;
  }

  return nullptr;
}

Element* Document::GetAnonymousElementByAttribute(Element& aElement,
                                                  const nsAString& aAttrName,
                                                  const nsAString& aAttrValue) {
  RefPtr<nsAtom> attribute = NS_Atomize(aAttrName);

  return GetAnonymousElementByAttribute(&aElement, attribute, aAttrValue);
}

nsINodeList* Document::GetAnonymousNodes(Element& aElement) {
  return BindingManager()->GetAnonymousNodesFor(&aElement);
}

already_AddRefed<nsRange> Document::CreateRange(ErrorResult& rv) {
  RefPtr<nsRange> range = new nsRange(this);
  nsresult res = range->CollapseTo(this, 0);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  return range.forget();
}

already_AddRefed<NodeIterator> Document::CreateNodeIterator(
    nsINode& aRoot, uint32_t aWhatToShow, NodeFilter* aFilter,
    ErrorResult& rv) const {
  RefPtr<NodeIterator> iterator =
      new NodeIterator(&aRoot, aWhatToShow, aFilter);
  return iterator.forget();
}

already_AddRefed<TreeWalker> Document::CreateTreeWalker(nsINode& aRoot,
                                                        uint32_t aWhatToShow,
                                                        NodeFilter* aFilter,
                                                        ErrorResult& rv) const {
  RefPtr<TreeWalker> walker = new TreeWalker(&aRoot, aWhatToShow, aFilter);
  return walker.forget();
}

already_AddRefed<Location> Document::GetLocation() const {
  nsCOMPtr<nsPIDOMWindowInner> w = do_QueryInterface(mScriptGlobalObject);

  if (!w) {
    return nullptr;
  }

  return do_AddRef(w->Location());
}

Element* Document::GetHtmlElement() const {
  Element* rootElement = GetRootElement();
  if (rootElement && rootElement->IsHTMLElement(nsGkAtoms::html))
    return rootElement;
  return nullptr;
}

Element* Document::GetHtmlChildElement(nsAtom* aTag) {
  Element* html = GetHtmlElement();
  if (!html) return nullptr;

  // Look for the element with aTag inside html. This needs to run
  // forwards to find the first such element.
  for (nsIContent* child = html->GetFirstChild(); child;
       child = child->GetNextSibling()) {
    if (child->IsHTMLElement(aTag)) return child->AsElement();
  }
  return nullptr;
}

nsGenericHTMLElement* Document::GetBody() {
  Element* html = GetHtmlElement();
  if (!html) {
    return nullptr;
  }

  for (nsIContent* child = html->GetFirstChild(); child;
       child = child->GetNextSibling()) {
    if (child->IsHTMLElement(nsGkAtoms::body) ||
        child->IsHTMLElement(nsGkAtoms::frameset)) {
      return static_cast<nsGenericHTMLElement*>(child);
    }
  }

  return nullptr;
}

void Document::SetBody(nsGenericHTMLElement* newBody, ErrorResult& rv) {
  nsCOMPtr<Element> root = GetRootElement();

  // The body element must be either a body tag or a frameset tag. And we must
  // have a root element to be able to add kids to it.
  if (!newBody ||
      !newBody->IsAnyOfHTMLElements(nsGkAtoms::body, nsGkAtoms::frameset) ||
      !root) {
    rv.Throw(NS_ERROR_DOM_HIERARCHY_REQUEST_ERR);
    return;
  }

  // Use DOM methods so that we pass through the appropriate security checks.
  nsCOMPtr<Element> currentBody = GetBody();
  if (currentBody) {
    root->ReplaceChild(*newBody, *currentBody, rv);
  } else {
    root->AppendChild(*newBody, rv);
  }
}

HTMLSharedElement* Document::GetHead() {
  return static_cast<HTMLSharedElement*>(GetHeadElement());
}

Element* Document::GetTitleElement() {
  // mMayHaveTitleElement will have been set to true if any HTML or SVG
  // <title> element has been bound to this document. So if it's false,
  // we know there is nothing to do here. This avoids us having to search
  // the whole DOM if someone calls document.title on a large document
  // without a title.
  if (!mMayHaveTitleElement) return nullptr;

  Element* root = GetRootElement();
  if (root && root->IsSVGElement(nsGkAtoms::svg)) {
    // In SVG, the document's title must be a child
    for (nsIContent* child = root->GetFirstChild(); child;
         child = child->GetNextSibling()) {
      if (child->IsSVGElement(nsGkAtoms::title)) {
        return child->AsElement();
      }
    }
    return nullptr;
  }

  // We check the HTML namespace even for non-HTML documents, except SVG.  This
  // matches the spec and the behavior of all tested browsers.
  // We avoid creating a live nsContentList since we don't need to watch for DOM
  // tree mutations.
  RefPtr<nsContentList> list = new nsContentList(
      this, kNameSpaceID_XHTML, nsGkAtoms::title, nsGkAtoms::title,
      /* aDeep = */ true,
      /* aLiveList = */ false);

  nsIContent* first = list->Item(0, false);

  return first ? first->AsElement() : nullptr;
}

void Document::GetTitle(nsAString& aTitle) {
  aTitle.Truncate();

  Element* rootElement = GetRootElement();
  if (!rootElement) {
    return;
  }

  nsAutoString tmp;

#ifdef MOZ_XUL
  if (rootElement->IsXULElement()) {
    rootElement->GetAttr(kNameSpaceID_None, nsGkAtoms::title, tmp);
  } else
#endif
  {
    Element* title = GetTitleElement();
    if (!title) {
      return;
    }
    nsContentUtils::GetNodeTextContent(title, false, tmp);
  }

  tmp.CompressWhitespace();
  aTitle = tmp;
}

void Document::SetTitle(const nsAString& aTitle, ErrorResult& aRv) {
  Element* rootElement = GetRootElement();
  if (!rootElement) {
    return;
  }

#ifdef MOZ_XUL
  if (rootElement->IsXULElement()) {
    aRv =
        rootElement->SetAttr(kNameSpaceID_None, nsGkAtoms::title, aTitle, true);
    return;
  }
#endif

  Maybe<mozAutoDocUpdate> updateBatch;
  nsCOMPtr<Element> title = GetTitleElement();
  if (rootElement->IsSVGElement(nsGkAtoms::svg)) {
    if (!title) {
      // Batch updates so that mutation events don't change "the title
      // element" under us
      updateBatch.emplace(this, true);
      RefPtr<mozilla::dom::NodeInfo> titleInfo = mNodeInfoManager->GetNodeInfo(
          nsGkAtoms::title, nullptr, kNameSpaceID_SVG, ELEMENT_NODE);
      NS_NewSVGElement(getter_AddRefs(title), titleInfo.forget(),
                       NOT_FROM_PARSER);
      if (!title) {
        return;
      }
      rootElement->InsertChildBefore(title, rootElement->GetFirstChild(), true);
    }
  } else if (rootElement->IsHTMLElement()) {
    if (!title) {
      // Batch updates so that mutation events don't change "the title
      // element" under us
      updateBatch.emplace(this, true);
      Element* head = GetHeadElement();
      if (!head) {
        return;
      }

      RefPtr<mozilla::dom::NodeInfo> titleInfo;
      titleInfo = mNodeInfoManager->GetNodeInfo(
          nsGkAtoms::title, nullptr, kNameSpaceID_XHTML, ELEMENT_NODE);
      title = NS_NewHTMLTitleElement(titleInfo.forget());
      if (!title) {
        return;
      }

      head->AppendChildTo(title, true);
    }
  } else {
    return;
  }

  aRv = nsContentUtils::SetNodeTextContent(title, aTitle, false);
}

void Document::NotifyPossibleTitleChange(bool aBoundTitleElement) {
  NS_ASSERTION(!mInUnlinkOrDeletion || !aBoundTitleElement,
               "Setting a title while unlinking or destroying the element?");
  if (mInUnlinkOrDeletion) {
    return;
  }

  if (aBoundTitleElement) {
    mMayHaveTitleElement = true;
  }
  if (mPendingTitleChangeEvent.IsPending()) return;

  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  RefPtr<nsRunnableMethod<Document, void, false>> event =
      NewNonOwningRunnableMethod("Document::DoNotifyPossibleTitleChange", this,
                                 &Document::DoNotifyPossibleTitleChange);
  nsresult rv = Dispatch(TaskCategory::Other, do_AddRef(event));
  if (NS_SUCCEEDED(rv)) {
    mPendingTitleChangeEvent = std::move(event);
  }
}

void Document::DoNotifyPossibleTitleChange() {
  mPendingTitleChangeEvent.Forget();
  mHaveFiredTitleChange = true;

  nsAutoString title;
  GetTitle(title);

  RefPtr<PresShell> presShell = GetPresShell();
  if (presShell) {
    nsCOMPtr<nsISupports> container =
        presShell->GetPresContext()->GetContainerWeak();
    if (container) {
      nsCOMPtr<nsIBaseWindow> docShellWin = do_QueryInterface(container);
      if (docShellWin) {
        docShellWin->SetTitle(title);
      }
    }
  }

  // Fire a DOM event for the title change.
  nsContentUtils::DispatchChromeEvent(this, ToSupports(this),
                                      NS_LITERAL_STRING("DOMTitleChanged"),
                                      CanBubble::eYes, Cancelable::eYes);
}

already_AddRefed<BoxObject> Document::GetBoxObjectFor(Element* aElement,
                                                      ErrorResult& aRv) {
  if (!aElement) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  Document* doc = aElement->OwnerDoc();
  if (doc != this) {
    aRv.Throw(NS_ERROR_DOM_WRONG_DOCUMENT_ERR);
    return nullptr;
  }

  if (!mHasWarnedAboutBoxObjects && !aElement->IsXULElement()) {
    mHasWarnedAboutBoxObjects = true;
    nsContentUtils::ReportToConsole(
        nsIScriptError::warningFlag, NS_LITERAL_CSTRING("BoxObjects"), this,
        nsContentUtils::eDOM_PROPERTIES, "UseOfGetBoxObjectForWarning");
  }

  if (!mBoxObjectTable) {
    mBoxObjectTable =
        new nsRefPtrHashtable<nsPtrHashKey<nsIContent>, BoxObject>(6);
  }

  RefPtr<BoxObject> boxObject;
  auto entry = mBoxObjectTable->LookupForAdd(aElement);
  if (entry) {
    boxObject = entry.Data();
    return boxObject.forget();
  }

  boxObject = new BoxObject();
  boxObject->Init(aElement);
  entry.OrInsert([&boxObject]() { return boxObject; });

  return boxObject.forget();
}

void Document::ClearBoxObjectFor(nsIContent* aContent) {
  if (mBoxObjectTable) {
    if (auto entry = mBoxObjectTable->Lookup(aContent)) {
      nsPIBoxObject* boxObject = entry.Data();
      boxObject->Clear();
      entry.Remove();
    }
  }
}

already_AddRefed<MediaQueryList> Document::MatchMedia(
    const nsAString& aMediaQueryList, CallerType aCallerType) {
  RefPtr<MediaQueryList> result =
      new MediaQueryList(this, aMediaQueryList, aCallerType);

  mDOMMediaQueryLists.insertBack(result);

  return result.forget();
}

void Document::SetMayStartLayout(bool aMayStartLayout) {
  mMayStartLayout = aMayStartLayout;
  if (MayStartLayout()) {
    // Before starting layout, check whether we're a toplevel chrome
    // window.  If we are, setup some state so that we don't have to restyle
    // the whole tree after StartLayout.
    if (nsCOMPtr<nsIXULWindow> win = GetXULWindowIfToplevelChrome()) {
      // We're the chrome document!
      win->BeforeStartLayout();
    }
    ReadyState state = GetReadyStateEnum();
    if (state >= READYSTATE_INTERACTIVE) {
      // DOMContentLoaded has fired already.
      MaybeResolveReadyForIdle();
    }
  }
}

nsresult Document::InitializeFrameLoader(nsFrameLoader* aLoader) {
  mInitializableFrameLoaders.RemoveElement(aLoader);
  // Don't even try to initialize.
  if (mInDestructor) {
    NS_WARNING(
        "Trying to initialize a frame loader while"
        "document is being deleted");
    return NS_ERROR_FAILURE;
  }

  mInitializableFrameLoaders.AppendElement(aLoader);
  if (!mFrameLoaderRunner) {
    mFrameLoaderRunner =
        NewRunnableMethod("Document::MaybeInitializeFinalizeFrameLoaders", this,
                          &Document::MaybeInitializeFinalizeFrameLoaders);
    NS_ENSURE_TRUE(mFrameLoaderRunner, NS_ERROR_OUT_OF_MEMORY);
    nsContentUtils::AddScriptRunner(mFrameLoaderRunner);
  }
  return NS_OK;
}

nsresult Document::FinalizeFrameLoader(nsFrameLoader* aLoader,
                                       nsIRunnable* aFinalizer) {
  mInitializableFrameLoaders.RemoveElement(aLoader);
  if (mInDestructor) {
    return NS_ERROR_FAILURE;
  }

  mFrameLoaderFinalizers.AppendElement(aFinalizer);
  if (!mFrameLoaderRunner) {
    mFrameLoaderRunner =
        NewRunnableMethod("Document::MaybeInitializeFinalizeFrameLoaders", this,
                          &Document::MaybeInitializeFinalizeFrameLoaders);
    NS_ENSURE_TRUE(mFrameLoaderRunner, NS_ERROR_OUT_OF_MEMORY);
    nsContentUtils::AddScriptRunner(mFrameLoaderRunner);
  }
  return NS_OK;
}

void Document::MaybeInitializeFinalizeFrameLoaders() {
  if (mDelayFrameLoaderInitialization || mUpdateNestLevel != 0) {
    // This method will be recalled when mUpdateNestLevel drops to 0,
    // or when !mDelayFrameLoaderInitialization.
    mFrameLoaderRunner = nullptr;
    return;
  }

  // We're not in an update, but it is not safe to run scripts, so
  // postpone frameloader initialization and finalization.
  if (!nsContentUtils::IsSafeToRunScript()) {
    if (!mInDestructor && !mFrameLoaderRunner &&
        (mInitializableFrameLoaders.Length() ||
         mFrameLoaderFinalizers.Length())) {
      mFrameLoaderRunner = NewRunnableMethod(
          "Document::MaybeInitializeFinalizeFrameLoaders", this,
          &Document::MaybeInitializeFinalizeFrameLoaders);
      nsContentUtils::AddScriptRunner(mFrameLoaderRunner);
    }
    return;
  }
  mFrameLoaderRunner = nullptr;

  // Don't use a temporary array for mInitializableFrameLoaders, because
  // loading a frame may cause some other frameloader to be removed from the
  // array. But be careful to keep the loader alive when starting the load!
  while (mInitializableFrameLoaders.Length()) {
    RefPtr<nsFrameLoader> loader = mInitializableFrameLoaders[0];
    mInitializableFrameLoaders.RemoveElementAt(0);
    NS_ASSERTION(loader, "null frameloader in the array?");
    loader->ReallyStartLoading();
  }

  uint32_t length = mFrameLoaderFinalizers.Length();
  if (length > 0) {
    nsTArray<nsCOMPtr<nsIRunnable>> finalizers;
    mFrameLoaderFinalizers.SwapElements(finalizers);
    for (uint32_t i = 0; i < length; ++i) {
      finalizers[i]->Run();
    }
  }
}

void Document::TryCancelFrameLoaderInitialization(nsIDocShell* aShell) {
  uint32_t length = mInitializableFrameLoaders.Length();
  for (uint32_t i = 0; i < length; ++i) {
    if (mInitializableFrameLoaders[i]->GetExistingDocShell() == aShell) {
      mInitializableFrameLoaders.RemoveElementAt(i);
      return;
    }
  }
}

void Document::SetPrototypeDocument(nsXULPrototypeDocument* aPrototype) {
  mPrototypeDocument = aPrototype;
}

Document* Document::RequestExternalResource(
    nsIURI* aURI, nsIURI* aReferrer, uint32_t aReferrerPolicy,
    nsINode* aRequestingNode, ExternalResourceLoad** aPendingLoad) {
  MOZ_ASSERT(aURI, "Must have a URI");
  MOZ_ASSERT(aRequestingNode, "Must have a node");
  if (mDisplayDocument) {
    return mDisplayDocument->RequestExternalResource(
        aURI, aReferrer, aReferrerPolicy, aRequestingNode, aPendingLoad);
  }

  return mExternalResourceMap.RequestResource(
      aURI, aReferrer, aReferrerPolicy, aRequestingNode, this, aPendingLoad);
}

void Document::EnumerateExternalResources(SubDocEnumFunc aCallback,
                                          void* aData) {
  mExternalResourceMap.EnumerateResources(aCallback, aData);
}

SMILAnimationController* Document::GetAnimationController() {
  // We create the animation controller lazily because most documents won't want
  // one and only SVG documents and the like will call this
  if (mAnimationController) return mAnimationController;
  // Refuse to create an Animation Controller for data documents.
  if (mLoadedAsData || mLoadedAsInteractiveData) return nullptr;

  mAnimationController = new SMILAnimationController(this);

  // If there's a presContext then check the animation mode and pause if
  // necessary.
  nsPresContext* context = GetPresContext();
  if (mAnimationController && context &&
      context->ImageAnimationMode() == imgIContainer::kDontAnimMode) {
    mAnimationController->Pause(SMILTimeContainer::PAUSE_USERPREF);
  }

  // If we're hidden (or being hidden), notify the newly-created animation
  // controller. (Skip this check for SVG-as-an-image documents, though,
  // because they don't get OnPageShow / OnPageHide calls).
  if (!mIsShowing && !mIsBeingUsedAsImage) {
    mAnimationController->OnPageHide();
  }

  return mAnimationController;
}

PendingAnimationTracker* Document::GetOrCreatePendingAnimationTracker() {
  if (!mPendingAnimationTracker) {
    mPendingAnimationTracker = new PendingAnimationTracker(this);
  }

  return mPendingAnimationTracker;
}

/**
 * Retrieve the "direction" property of the document.
 *
 * @lina 01/09/2001
 */
void Document::GetDir(nsAString& aDirection) const {
  aDirection.Truncate();
  Element* rootElement = GetHtmlElement();
  if (rootElement) {
    static_cast<nsGenericHTMLElement*>(rootElement)->GetDir(aDirection);
  }
}

/**
 * Set the "direction" property of the document.
 *
 * @lina 01/09/2001
 */
void Document::SetDir(const nsAString& aDirection) {
  Element* rootElement = GetHtmlElement();
  if (rootElement) {
    rootElement->SetAttr(kNameSpaceID_None, nsGkAtoms::dir, aDirection, true);
  }
}

nsIHTMLCollection* Document::Images() {
  if (!mImages) {
    mImages = new nsContentList(this, kNameSpaceID_XHTML, nsGkAtoms::img,
                                nsGkAtoms::img);
  }
  return mImages;
}

nsIHTMLCollection* Document::Embeds() {
  if (!mEmbeds) {
    mEmbeds = new nsContentList(this, kNameSpaceID_XHTML, nsGkAtoms::embed,
                                nsGkAtoms::embed);
  }
  return mEmbeds;
}

static bool MatchLinks(Element* aElement, int32_t aNamespaceID, nsAtom* aAtom,
                       void* aData) {
  return aElement->IsAnyOfHTMLElements(nsGkAtoms::a, nsGkAtoms::area) &&
         aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::href);
}

nsIHTMLCollection* Document::Links() {
  if (!mLinks) {
    mLinks = new nsContentList(this, MatchLinks, nullptr, nullptr);
  }
  return mLinks;
}

nsIHTMLCollection* Document::Forms() {
  if (!mForms) {
    // Please keep this in sync with nsHTMLDocument::GetFormsAndFormControls.
    mForms = new nsContentList(this, kNameSpaceID_XHTML, nsGkAtoms::form,
                               nsGkAtoms::form);
  }

  return mForms;
}

nsIHTMLCollection* Document::Scripts() {
  if (!mScripts) {
    mScripts = new nsContentList(this, kNameSpaceID_XHTML, nsGkAtoms::script,
                                 nsGkAtoms::script);
  }
  return mScripts;
}

nsIHTMLCollection* Document::Applets() {
  if (!mApplets) {
    mApplets = new nsEmptyContentList(this);
  }
  return mApplets;
}

static bool MatchAnchors(Element* aElement, int32_t aNamespaceID, nsAtom* aAtom,
                         void* aData) {
  return aElement->IsHTMLElement(nsGkAtoms::a) &&
         aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::name);
}

nsIHTMLCollection* Document::Anchors() {
  if (!mAnchors) {
    mAnchors = new nsContentList(this, MatchAnchors, nullptr, nullptr);
  }
  return mAnchors;
}

/* static */
bool Document::MatchNameAttribute(Element* aElement, int32_t aNamespaceID,
                                  nsAtom* aAtom, void* aData) {
  MOZ_ASSERT(aElement, "Must have element to work with!");

  if (!aElement->HasName()) {
    return false;
  }

  nsString* elementName = static_cast<nsString*>(aData);
  return aElement->GetNameSpaceID() == kNameSpaceID_XHTML &&
         aElement->AttrValueIs(kNameSpaceID_None, nsGkAtoms::name, *elementName,
                               eCaseMatters);
}

/* static */
void* Document::UseExistingNameString(nsINode* aRootNode,
                                      const nsString* aName) {
  return const_cast<nsString*>(aName);
}

nsresult Document::GetDocumentURI(nsString& aDocumentURI) const {
  if (mDocumentURI) {
    nsAutoCString uri;
    nsresult rv = mDocumentURI->GetSpec(uri);
    NS_ENSURE_SUCCESS(rv, rv);

    CopyUTF8toUTF16(uri, aDocumentURI);
  } else {
    aDocumentURI.Truncate();
  }

  return NS_OK;
}

// Alias of above
nsresult Document::GetURL(nsString& aURL) const { return GetDocumentURI(aURL); }

void Document::GetDocumentURIFromJS(nsString& aDocumentURI,
                                    CallerType aCallerType,
                                    ErrorResult& aRv) const {
  if (!mChromeXHRDocURI || aCallerType != CallerType::System) {
    aRv = GetDocumentURI(aDocumentURI);
    return;
  }

  nsAutoCString uri;
  nsresult res = mChromeXHRDocURI->GetSpec(uri);
  if (NS_FAILED(res)) {
    aRv.Throw(res);
    return;
  }
  CopyUTF8toUTF16(uri, aDocumentURI);
}

nsIURI* Document::GetDocumentURIObject() const {
  if (!mChromeXHRDocURI) {
    return GetDocumentURI();
  }

  return mChromeXHRDocURI;
}

void Document::GetCompatMode(nsString& aCompatMode) const {
  NS_ASSERTION(mCompatMode == eCompatibility_NavQuirks ||
                   mCompatMode == eCompatibility_AlmostStandards ||
                   mCompatMode == eCompatibility_FullStandards,
               "mCompatMode is neither quirks nor strict for this document");

  if (mCompatMode == eCompatibility_NavQuirks) {
    aCompatMode.AssignLiteral("BackCompat");
  } else {
    aCompatMode.AssignLiteral("CSS1Compat");
  }
}

}  // namespace dom
}  // namespace mozilla

void nsDOMAttributeMap::BlastSubtreeToPieces(nsINode* aNode) {
  if (Element* element = Element::FromNode(aNode)) {
    if (const nsDOMAttributeMap* map = element->GetAttributeMap()) {
      while (true) {
        RefPtr<Attr> attr;
        {
          // Use an iterator to get an arbitrary attribute from the
          // cache. The iterator must be destroyed before any other
          // operations on mAttributeCache, to avoid hash table
          // assertions.
          auto iter = map->mAttributeCache.ConstIter();
          if (iter.Done()) {
            break;
          }
          attr = iter.UserData();
        }

        BlastSubtreeToPieces(attr);

        mozilla::DebugOnly<nsresult> rv =
            element->UnsetAttr(attr->NodeInfo()->NamespaceID(),
                               attr->NodeInfo()->NameAtom(), false);

        // XXX Should we abort here?
        NS_ASSERTION(NS_SUCCEEDED(rv), "Uh-oh, UnsetAttr shouldn't fail!");
      }
    }

    if (mozilla::dom::ShadowRoot* shadow = element->GetShadowRoot()) {
      BlastSubtreeToPieces(shadow);
      element->UnattachShadow();
    }
  }

  while (aNode->HasChildren()) {
    nsIContent* node = aNode->GetFirstChild();
    BlastSubtreeToPieces(node);
    aNode->RemoveChildNode(node, false);
  }
}

namespace mozilla {
namespace dom {

nsINode* Document::AdoptNode(nsINode& aAdoptedNode, ErrorResult& rv) {
  nsINode* adoptedNode = &aAdoptedNode;

  // Scope firing mutation events so that we don't carry any state that
  // might be stale
  {
    nsINode* parent = adoptedNode->GetParentNode();
    if (parent) {
      nsContentUtils::MaybeFireNodeRemoved(adoptedNode, parent);
    }
  }

  nsAutoScriptBlocker scriptBlocker;

  switch (adoptedNode->NodeType()) {
    case ATTRIBUTE_NODE: {
      // Remove from ownerElement.
      RefPtr<Attr> adoptedAttr = static_cast<Attr*>(adoptedNode);

      nsCOMPtr<Element> ownerElement = adoptedAttr->GetOwnerElement(rv);
      if (rv.Failed()) {
        return nullptr;
      }

      if (ownerElement) {
        RefPtr<Attr> newAttr =
            ownerElement->RemoveAttributeNode(*adoptedAttr, rv);
        if (rv.Failed()) {
          return nullptr;
        }

        newAttr.swap(adoptedAttr);
      }

      break;
    }
    case DOCUMENT_FRAGMENT_NODE: {
      if (adoptedNode->IsShadowRoot()) {
        rv.Throw(NS_ERROR_DOM_HIERARCHY_REQUEST_ERR);
        return nullptr;
      }
      MOZ_FALLTHROUGH;
    }
    case ELEMENT_NODE:
    case PROCESSING_INSTRUCTION_NODE:
    case TEXT_NODE:
    case CDATA_SECTION_NODE:
    case COMMENT_NODE:
    case DOCUMENT_TYPE_NODE: {
      // Don't allow adopting a node's anonymous subtree out from under it.
      if (adoptedNode->AsContent()->IsRootOfAnonymousSubtree()) {
        rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
        return nullptr;
      }

      // We don't want to adopt an element into its own contentDocument or into
      // a descendant contentDocument, so we check if the frameElement of this
      // document or any of its parents is the adopted node or one of its
      // descendants.
      Document* doc = this;
      do {
        if (nsPIDOMWindowOuter* win = doc->GetWindow()) {
          nsCOMPtr<nsINode> node = win->GetFrameElementInternal();
          if (node &&
              nsContentUtils::ContentIsDescendantOf(node, adoptedNode)) {
            rv.Throw(NS_ERROR_DOM_HIERARCHY_REQUEST_ERR);
            return nullptr;
          }
        }
      } while ((doc = doc->GetParentDocument()));

      // Remove from parent.
      nsCOMPtr<nsINode> parent = adoptedNode->GetParentNode();
      if (parent) {
        parent->RemoveChildNode(adoptedNode->AsContent(), true);
      } else {
        MOZ_ASSERT(!adoptedNode->IsInUncomposedDoc());

        // If we're adopting a node that's not in a document, it might still
        // have a binding applied. Remove the binding from the element now
        // that it's getting adopted into a new document.
        // TODO Fully tear down the binding.
        if (Element* element = Element::FromNode(adoptedNode)) {
          element->SetXBLBinding(nullptr);
        }
      }

      break;
    }
    case DOCUMENT_NODE: {
      rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
      return nullptr;
    }
    default: {
      NS_WARNING("Don't know how to adopt this nodetype for adoptNode.");

      rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
      return nullptr;
    }
  }

  nsCOMPtr<Document> oldDocument = adoptedNode->OwnerDoc();
  bool sameDocument = oldDocument == this;

  AutoJSContext cx;
  JS::Rooted<JSObject*> newScope(cx, nullptr);
  if (!sameDocument) {
    newScope = GetWrapper();
    if (!newScope && GetScopeObject() && GetScopeObject()->HasJSGlobal()) {
      // Make sure cx is in a semi-sane compartment before we call WrapNative.
      // It's kind of irrelevant, given that we're passing aAllowWrapping =
      // false, and documents should always insist on being wrapped in an
      // canonical scope. But we try to pass something sane anyway.
      JSObject* globalObject = GetScopeObject()->GetGlobalJSObject();
      JSAutoRealm ar(cx, globalObject);
      JS::Rooted<JS::Value> v(cx);
      rv = nsContentUtils::WrapNative(cx, ToSupports(this), this, &v,
                                      /* aAllowWrapping = */ false);
      if (rv.Failed()) return nullptr;
      newScope = &v.toObject();
    }
  }

  nsCOMArray<nsINode> nodesWithProperties;
  nsNodeUtils::Adopt(adoptedNode, sameDocument ? nullptr : mNodeInfoManager,
                     newScope, nodesWithProperties, rv);
  if (rv.Failed()) {
    // Disconnect all nodes from their parents, since some have the old document
    // as their ownerDocument and some have this as their ownerDocument.
    nsDOMAttributeMap::BlastSubtreeToPieces(adoptedNode);

    if (!sameDocument && oldDocument) {
      for (nsINode* node : nodesWithProperties) {
        // Remove all properties.
        oldDocument->PropertyTable().DeleteAllPropertiesFor(node);
      }
    }

    return nullptr;
  }

  if (!sameDocument && oldDocument) {
    nsPropertyTable& oldTable = oldDocument->PropertyTable();
    nsPropertyTable& newTable = PropertyTable();
    for (nsINode* node : nodesWithProperties) {
      rv = oldTable.TransferOrDeleteAllPropertiesFor(node, newTable);
    }

    if (rv.Failed()) {
      // Disconnect all nodes from their parents.
      nsDOMAttributeMap::BlastSubtreeToPieces(adoptedNode);

      return nullptr;
    }
  }

  NS_ASSERTION(adoptedNode->OwnerDoc() == this,
               "Should still be in the document we just got adopted into");

  return adoptedNode;
}

bool Document::UseWidthDeviceWidthFallbackViewport() const { return false; }

void Document::ParseWidthAndHeightInMetaViewport(
    const nsAString& aWidthString, const nsAString& aHeightString,
    const nsAString& aScaleString) {
  // The width and height properties
  // https://drafts.csswg.org/css-device-adapt/#width-and-height-properties
  //
  // The width and height viewport <META> properties are translated into width
  // and height descriptors, setting the min-width/min-height value to
  // extend-to-zoom and the max-width/max-height value to the length from the
  // viewport <META> property as follows:
  //
  // 1. Non-negative number values are translated to pixel lengths, clamped to
  //    the range: [1px, 10000px]
  // 2. Negative number values are dropped
  // 3. device-width and device-height translate to 100vw and 100vh respectively
  // 4. Other keywords and unknown values translate to 1px
  mMinWidth = nsViewportInfo::Auto;
  mMaxWidth = nsViewportInfo::Auto;
  if (!aWidthString.IsEmpty()) {
    mMinWidth = nsViewportInfo::ExtendToZoom;
    if (aWidthString.EqualsLiteral("device-width")) {
      mMaxWidth = nsViewportInfo::DeviceSize;
    } else {
      nsresult widthErrorCode;
      mMaxWidth = aWidthString.ToInteger(&widthErrorCode);
      if (NS_FAILED(widthErrorCode)) {
        mMaxWidth = 1.0f;
      } else if (mMaxWidth >= 0.0f) {
        mMaxWidth = clamped(mMaxWidth, CSSCoord(1.0f), CSSCoord(10000.0f));
      } else {
        mMaxWidth = nsViewportInfo::Auto;
      }
    }
    // FIXME: Check the scale is not 'auto' once we support auto value for it.
  } else if (!aScaleString.IsEmpty()) {
    if (aHeightString.IsEmpty()) {
      mMinWidth = nsViewportInfo::ExtendToZoom;
      mMaxWidth = nsViewportInfo::ExtendToZoom;
    }
  } else if (aHeightString.IsEmpty() && UseWidthDeviceWidthFallbackViewport()) {
    mMinWidth = nsViewportInfo::ExtendToZoom;
    mMaxWidth = nsViewportInfo::DeviceSize;
  }

  mMinHeight = nsViewportInfo::Auto;
  mMaxHeight = nsViewportInfo::Auto;
  if (!aHeightString.IsEmpty()) {
    mMinHeight = nsViewportInfo::ExtendToZoom;
    if (aHeightString.EqualsLiteral("device-height")) {
      mMaxHeight = nsViewportInfo::DeviceSize;
    } else {
      nsresult heightErrorCode;
      mMaxHeight = aHeightString.ToInteger(&heightErrorCode);
      if (NS_FAILED(heightErrorCode)) {
        mMaxHeight = 1.0f;
      } else if (mMaxHeight >= 0.0f) {
        mMaxHeight = clamped(mMaxHeight, CSSCoord(1.0f), CSSCoord(10000.0f));
      } else {
        mMaxHeight = nsViewportInfo::Auto;
      }
    }
  }
}

nsViewportInfo Document::GetViewportInfo(const ScreenIntSize& aDisplaySize) {
  MOZ_ASSERT(mPresShell);

  // Compute the CSS-to-LayoutDevice pixel scale as the product of the
  // widget scale and the full zoom.
  nsPresContext* context = mPresShell->GetPresContext();
  // When querying the full zoom, get it from the device context rather than
  // directly from the pres context, because the device context's value can
  // include an adjustment necessay to keep the number of app units per device
  // pixel an integer, and we want the adjusted value.
  float fullZoom = context ? context->DeviceContext()->GetFullZoom() : 1.0;
  fullZoom = (fullZoom == 0.0) ? 1.0 : fullZoom;
  CSSToLayoutDeviceScale layoutDeviceScale =
      context ? context->CSSToDevPixelScale() : CSSToLayoutDeviceScale(1);

  CSSToScreenScale defaultScale =
      layoutDeviceScale * LayoutDeviceToScreenScale(1.0);

  // Special behaviour for desktop mode, provided we are not on an about: page
  nsPIDOMWindowOuter* win = GetWindow();
  if (win && win->IsDesktopModeViewport() && !IsAboutPage()) {
    CSSCoord viewportWidth = gfxPrefs::DesktopViewportWidth() / fullZoom;
    CSSToScreenScale scaleToFit(aDisplaySize.width / viewportWidth);
    float aspectRatio = (float)aDisplaySize.height / aDisplaySize.width;
    CSSSize viewportSize(viewportWidth, viewportWidth * aspectRatio);
    ScreenIntSize fakeDesktopSize = RoundedToInt(viewportSize * scaleToFit);
    return nsViewportInfo(fakeDesktopSize, scaleToFit,
                          nsViewportInfo::ZoomFlag::AllowZoom);
  }

  if (!nsLayoutUtils::ShouldHandleMetaViewport(this)) {
    return nsViewportInfo(aDisplaySize, defaultScale,
                          nsLayoutUtils::AllowZoomingForDocument(this)
                              ? nsViewportInfo::ZoomFlag::AllowZoom
                              : nsViewportInfo::ZoomFlag::DisallowZoom);
  }

  // In cases where the width of the CSS viewport is less than or equal to the
  // width of the display (i.e. width <= device-width) then we disable
  // double-tap-to-zoom behaviour. See bug 941995 for details.

  switch (mViewportType) {
    case DisplayWidthHeight:
      return nsViewportInfo(aDisplaySize, defaultScale,
                            nsViewportInfo::ZoomFlag::AllowZoom);
    case Unknown: {
      nsAutoString viewport;
      GetHeaderData(nsGkAtoms::viewport, viewport);
      // We might early exit if the viewport is empty. Even if we don't,
      // at the end of this case we'll note that it was empty. Later, when
      // we're using the cached values, this will trigger alternate code paths.
      bool viewportIsEmpty = viewport.IsEmpty();
      if (viewportIsEmpty) {
        // If the docType specifies that we are on a site optimized for mobile,
        // then we want to return specially crafted defaults for the viewport
        // info.
        RefPtr<DocumentType> docType = GetDoctype();
        if (docType) {
          nsAutoString docId;
          docType->GetPublicId(docId);
          if ((docId.Find("WAP") != -1) || (docId.Find("Mobile") != -1) ||
              (docId.Find("WML") != -1)) {
            // We're making an assumption that the docType can't change here
            mViewportType = DisplayWidthHeight;
            return nsViewportInfo(aDisplaySize, defaultScale,
                                  nsViewportInfo::ZoomFlag::AllowZoom);
          }
        }

        nsAutoString handheldFriendly;
        GetHeaderData(nsGkAtoms::handheldFriendly, handheldFriendly);
        if (handheldFriendly.EqualsLiteral("true")) {
          mViewportType = DisplayWidthHeight;
          return nsViewportInfo(aDisplaySize, defaultScale,
                                nsViewportInfo::ZoomFlag::AllowZoom);
        }
      }

      nsAutoString minScaleStr;
      GetHeaderData(nsGkAtoms::viewport_minimum_scale, minScaleStr);

      nsresult scaleMinErrorCode;
      mScaleMinFloat =
          LayoutDeviceToScreenScale(minScaleStr.ToFloat(&scaleMinErrorCode));

      if (NS_FAILED(scaleMinErrorCode)) {
        mScaleMinFloat = kViewportMinScale;
      }

      mScaleMinFloat = mozilla::clamped(mScaleMinFloat, kViewportMinScale,
                                        kViewportMaxScale);

      nsAutoString maxScaleStr;
      GetHeaderData(nsGkAtoms::viewport_maximum_scale, maxScaleStr);

      // We define a special error code variable for the scale and max scale,
      // because they are used later (see the width calculations).
      nsresult scaleMaxErrorCode;
      mScaleMaxFloat =
          LayoutDeviceToScreenScale(maxScaleStr.ToFloat(&scaleMaxErrorCode));

      if (NS_FAILED(scaleMaxErrorCode)) {
        mScaleMaxFloat = kViewportMaxScale;
      }

      // Resolve min-zoom and max-zoom values.
      // https://drafts.csswg.org/css-device-adapt/#constraining-min-max-zoom
      if (NS_SUCCEEDED(scaleMaxErrorCode) && NS_SUCCEEDED(scaleMinErrorCode)) {
        mScaleMaxFloat = std::max(mScaleMinFloat, mScaleMaxFloat);
      }

      mScaleMaxFloat = mozilla::clamped(mScaleMaxFloat, kViewportMinScale,
                                        kViewportMaxScale);

      nsAutoString scaleStr;
      GetHeaderData(nsGkAtoms::viewport_initial_scale, scaleStr);

      nsresult scaleErrorCode;
      mScaleFloat =
          LayoutDeviceToScreenScale(scaleStr.ToFloat(&scaleErrorCode));

      nsAutoString widthStr, heightStr;

      GetHeaderData(nsGkAtoms::viewport_height, heightStr);
      GetHeaderData(nsGkAtoms::viewport_width, widthStr);

      // Parse width and height properties
      // This function sets m{Min,Max}{Width,Height}.
      ParseWidthAndHeightInMetaViewport(widthStr, heightStr, scaleStr);

      mAllowZoom = true;
      nsAutoString userScalable;
      GetHeaderData(nsGkAtoms::viewport_user_scalable, userScalable);

      if ((userScalable.EqualsLiteral("0")) ||
          (userScalable.EqualsLiteral("no")) ||
          (userScalable.EqualsLiteral("false"))) {
        mAllowZoom = false;
      }

      mScaleStrEmpty = scaleStr.IsEmpty();
      mWidthStrEmpty = widthStr.IsEmpty();
      mValidScaleFloat = !scaleStr.IsEmpty() && NS_SUCCEEDED(scaleErrorCode);
      mValidMaxScale =
          !maxScaleStr.IsEmpty() && NS_SUCCEEDED(scaleMaxErrorCode);

      mViewportType = viewportIsEmpty ? Empty : Specified;
      MOZ_FALLTHROUGH;
    }
    case Specified:
    case Empty:
    default:
      LayoutDeviceToScreenScale effectiveMinScale = mScaleMinFloat;
      LayoutDeviceToScreenScale effectiveMaxScale = mScaleMaxFloat;
      bool effectiveValidMaxScale = mValidMaxScale;

      nsViewportInfo::ZoomFlag effectiveZoomFlag =
          mAllowZoom ? nsViewportInfo::ZoomFlag::AllowZoom
                     : nsViewportInfo::ZoomFlag::DisallowZoom;
      if (gfxPrefs::ForceUserScalable()) {
        // If the pref to force user-scalable is enabled, we ignore the values
        // from the meta-viewport tag for these properties and just assume they
        // allow the page to be scalable. Note in particular that this code is
        // in the "Specified" branch of the enclosing switch statement, so that
        // calls to GetViewportInfo always use the latest value of the
        // ForceUserScalable pref. Other codepaths that return nsViewportInfo
        // instances are all consistent with ForceUserScalable() already.
        effectiveMinScale = kViewportMinScale;
        effectiveMaxScale = kViewportMaxScale;
        effectiveValidMaxScale = true;
        effectiveZoomFlag = nsViewportInfo::ZoomFlag::AllowZoom;
      }

      // Returns extend-zoom value which is MIN(mScaleFloat, mScaleMaxFloat).
      auto ComputeExtendZoom = [&]() -> float {
        if (mValidScaleFloat && effectiveValidMaxScale) {
          return std::min(mScaleFloat.scale, effectiveMaxScale.scale);
        }
        if (mValidScaleFloat) {
          return mScaleFloat.scale;
        }
        if (effectiveValidMaxScale) {
          return effectiveMaxScale.scale;
        }
        return nsViewportInfo::Auto;
      };

      // Resolving 'extend-to-zoom'
      // https://drafts.csswg.org/css-device-adapt/#resolve-extend-to-zoom
      float extendZoom = ComputeExtendZoom();

      CSSCoord minWidth = mMinWidth;
      CSSCoord maxWidth = mMaxWidth;
      CSSCoord minHeight = mMinHeight;
      CSSCoord maxHeight = mMaxHeight;

      // aDisplaySize is in screen pixels; convert them to CSS pixels for the
      // viewport size. We need to use this scaled size for any clamping of
      // width or height.
      CSSSize displaySize = ScreenSize(aDisplaySize) / defaultScale;

      // Resolve device-width and device-height first.
      if (maxWidth == nsViewportInfo::DeviceSize) {
        maxWidth = displaySize.width;
      }
      if (maxHeight == nsViewportInfo::DeviceSize) {
        maxHeight = displaySize.height;
      }
      if (extendZoom == nsViewportInfo::Auto) {
        if (maxWidth == nsViewportInfo::ExtendToZoom) {
          maxWidth = nsViewportInfo::Auto;
        }
        if (maxHeight == nsViewportInfo::ExtendToZoom) {
          maxHeight = nsViewportInfo::Auto;
        }
        if (minWidth == nsViewportInfo::ExtendToZoom) {
          minWidth = maxWidth;
        }
        if (minHeight == nsViewportInfo::ExtendToZoom) {
          minHeight = maxHeight;
        }
      } else {
        CSSSize extendSize = displaySize / extendZoom;
        if (maxWidth == nsViewportInfo::ExtendToZoom) {
          maxWidth = extendSize.width;
        }
        if (maxHeight == nsViewportInfo::ExtendToZoom) {
          maxHeight = extendSize.height;
        }
        if (minWidth == nsViewportInfo::ExtendToZoom) {
          minWidth = nsViewportInfo::Max(extendSize.width, maxWidth);
        }
        if (minHeight == nsViewportInfo::ExtendToZoom) {
          minHeight = nsViewportInfo::Max(extendSize.height, maxHeight);
        }
      }
      // Resolve initial width and height from min/max descriptors
      // https://drafts.csswg.org/css-device-adapt/#resolve-initial-width-height
      CSSCoord width = nsViewportInfo::Auto;
      if (minWidth != nsViewportInfo::Auto ||
          maxWidth != nsViewportInfo::Auto) {
        width = nsViewportInfo::Max(
            minWidth, nsViewportInfo::Min(maxWidth, displaySize.width));
      }
      CSSCoord height = nsViewportInfo::Auto;
      if (minHeight != nsViewportInfo::Auto ||
          maxHeight != nsViewportInfo::Auto) {
        height = nsViewportInfo::Max(
            minHeight, nsViewportInfo::Min(maxHeight, displaySize.height));
      }

      // Resolve width value
      // https://drafts.csswg.org/css-device-adapt/#resolve-width
      if (width == nsViewportInfo::Auto) {
        if (height == nsViewportInfo::Auto || aDisplaySize.height == 0) {
          // What we do in this situation deviates somewhat from the spec. We
          // want to consider the case where no viewport information has been
          // provided, in which case we want to assume that the document is not
          // optimized for aDisplaySize, and we should instead force a useful
          // size.
          if (mViewportType == Empty) {
            // If we don't have any applicable viewport width constraints, this
            // is most likely a desktop page written without mobile devices in
            // mind. We use the desktop mode viewport for those pages by
            // default, because a narrow viewport based on typical mobile device
            // screen sizes (especially in portrait mode) will frequently break
            // the layout of such pages. To keep text readable in that case, we
            // rely on font inflation instead.

            // Divide by fullZoom to stretch CSS pixel size of viewport in order
            // to keep device pixel size unchanged after full zoom applied.
            // See bug 974242.
            width = gfxPrefs::DesktopViewportWidth() / fullZoom;
          } else {
            // Some viewport information was provided; follow the spec.
            width = displaySize.width;
          }
        } else {
          width = height * aDisplaySize.width / aDisplaySize.height;
        }
      }

      // Resolve height value
      // https://drafts.csswg.org/css-device-adapt/#resolve-height
      if (height == nsViewportInfo::Auto) {
        if (aDisplaySize.width == 0) {
          height = displaySize.height;
        } else {
          height = width * aDisplaySize.height / aDisplaySize.width;
        }
      }
      MOZ_ASSERT(width != nsViewportInfo::Auto &&
                 height != nsViewportInfo::Auto);

      CSSSize size(width, height);

      CSSToScreenScale scaleFloat = mScaleFloat * layoutDeviceScale;
      CSSToScreenScale scaleMinFloat = effectiveMinScale * layoutDeviceScale;
      CSSToScreenScale scaleMaxFloat = effectiveMaxScale * layoutDeviceScale;

      nsViewportInfo::AutoSizeFlag sizeFlag =
          nsViewportInfo::AutoSizeFlag::FixedSize;
      if (mMaxWidth == nsViewportInfo::DeviceSize ||
          (mWidthStrEmpty && (mMaxHeight == nsViewportInfo::DeviceSize ||
                              mScaleFloat.scale == 1.0f)) ||
          (!mWidthStrEmpty && mMaxWidth == nsViewportInfo::Auto &&
           mMaxHeight < 0)) {
        sizeFlag = nsViewportInfo::AutoSizeFlag::AutoSize;
      }

      // FIXME: Resolving width and height should be done above 'Resolve width
      // value' and 'Resolve height value'.
      if (sizeFlag == nsViewportInfo::AutoSizeFlag::AutoSize) {
        size = displaySize;
      }

      // The purpose of clamping the viewport width to a minimum size is to
      // prevent page authors from setting it to a ridiculously small value.
      // If the page is actually being rendered in a very small area (as might
      // happen in e.g. Android 8's picture-in-picture mode), we don't want to
      // prevent the viewport from taking on that size.
      CSSSize effectiveMinSize = Min(CSSSize(kViewportMinSize), displaySize);

      size.width = clamped(size.width, effectiveMinSize.width,
                           float(kViewportMaxSize.width));

      // Also recalculate the default zoom, if it wasn't specified in the
      // metadata, and the width is specified.
      if (mScaleStrEmpty && !mWidthStrEmpty) {
        CSSToScreenScale bestFitScale(float(aDisplaySize.width) / size.width);
        scaleFloat = (scaleFloat > bestFitScale) ? scaleFloat : bestFitScale;
      }

      size.height = clamped(size.height, effectiveMinSize.height,
                            float(kViewportMaxSize.height));

      // We need to perform a conversion, but only if the initial or maximum
      // scale were set explicitly by the user.
      if (mValidScaleFloat && scaleFloat >= scaleMinFloat &&
          scaleFloat <= scaleMaxFloat) {
        CSSSize displaySize = ScreenSize(aDisplaySize) / scaleFloat;
        size.width = std::max(size.width, displaySize.width);
        size.height = std::max(size.height, displaySize.height);
      } else if (effectiveValidMaxScale) {
        CSSSize displaySize = ScreenSize(aDisplaySize) / scaleMaxFloat;
        size.width = std::max(size.width, displaySize.width);
        size.height = std::max(size.height, displaySize.height);
      }

      return nsViewportInfo(
          scaleFloat, scaleMinFloat, scaleMaxFloat, size, sizeFlag,
          mValidScaleFloat ? nsViewportInfo::AutoScaleFlag::FixedScale
                           : nsViewportInfo::AutoScaleFlag::AutoScale,
          effectiveZoomFlag);
  }
}

void Document::UpdateForScrollAnchorAdjustment(nscoord aLength) {
  mScrollAnchorAdjustmentLength += abs(aLength);
  mScrollAnchorAdjustmentCount += 1;
}

EventListenerManager* Document::GetOrCreateListenerManager() {
  if (!mListenerManager) {
    mListenerManager =
        new EventListenerManager(static_cast<EventTarget*>(this));
    SetFlags(NODE_HAS_LISTENERMANAGER);
  }

  return mListenerManager;
}

EventListenerManager* Document::GetExistingListenerManager() const {
  return mListenerManager;
}

void Document::GetEventTargetParent(EventChainPreVisitor& aVisitor) {
  if (mDocGroup && aVisitor.mEvent->mMessage != eVoidEvent &&
      !mIgnoreDocGroupMismatches) {
    mDocGroup->ValidateAccess();
  }

  aVisitor.mCanHandle = true;
  // FIXME! This is a hack to make middle mouse paste working also in Editor.
  // Bug 329119
  aVisitor.mForceContentDispatch = true;

  // Load events must not propagate to |window| object, see bug 335251.
  if (aVisitor.mEvent->mMessage != eLoad) {
    nsGlobalWindowOuter* window = nsGlobalWindowOuter::Cast(GetWindow());
    aVisitor.SetParentTarget(
        window ? window->GetTargetForEventTargetChain() : nullptr, false);
  }
}

already_AddRefed<Event> Document::CreateEvent(const nsAString& aEventType,
                                              CallerType aCallerType,
                                              ErrorResult& rv) const {
  nsPresContext* presContext = GetPresContext();

  // Create event even without presContext.
  RefPtr<Event> ev =
      EventDispatcher::CreateEvent(const_cast<Document*>(this), presContext,
                                   nullptr, aEventType, aCallerType);
  if (!ev) {
    rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
    return nullptr;
  }
  WidgetEvent* e = ev->WidgetEventPtr();
  e->mFlags.mBubbles = false;
  e->mFlags.mCancelable = false;
  return ev.forget();
}

void Document::FlushPendingNotifications(FlushType aType) {
  mozilla::ChangesToFlush flush(aType, aType >= FlushType::Style);
  FlushPendingNotifications(flush);
}

class nsDocumentOnStack {
 public:
  explicit nsDocumentOnStack(Document* aDoc) : mDoc(aDoc) {
    mDoc->IncreaseStackRefCnt();
  }
  ~nsDocumentOnStack() { mDoc->DecreaseStackRefCnt(); }

 private:
  Document* mDoc;
};

void Document::FlushPendingNotifications(mozilla::ChangesToFlush aFlush) {
  FlushType flushType = aFlush.mFlushType;

  nsDocumentOnStack dos(this);

  // We need to flush the sink for non-HTML documents (because the XML
  // parser still does insertion with deferred notifications).  We
  // also need to flush the sink if this is a layout-related flush, to
  // make sure that layout is started as needed.  But we can skip that
  // part if we have no presshell or if it's already done an initial
  // reflow.
  if ((!IsHTMLDocument() || (flushType > FlushType::ContentAndNotify &&
                             mPresShell && !mPresShell->DidInitialize())) &&
      (mParser || mWeakSink)) {
    nsCOMPtr<nsIContentSink> sink;
    if (mParser) {
      sink = mParser->GetContentSink();
    } else {
      sink = do_QueryReferent(mWeakSink);
      if (!sink) {
        mWeakSink = nullptr;
      }
    }
    // Determine if it is safe to flush the sink notifications
    // by determining if it safe to flush all the presshells.
    if (sink && (flushType == FlushType::Content || IsSafeToFlush())) {
      sink->FlushPendingNotifications(flushType);
    }
  }

  // Should we be flushing pending binding constructors in here?

  if (flushType <= FlushType::ContentAndNotify) {
    // Nothing to do here
    return;
  }

  // If we have a parent we must flush the parent too to ensure that our
  // container is reflowed if its size was changed.  But if it's not safe to
  // flush ourselves, then don't flush the parent, since that can cause things
  // like resizes of our frame's widget, which we can't handle while flushing
  // is unsafe.
  // Since media queries mean that a size change of our container can
  // affect style, we need to promote a style flush on ourself to a
  // layout flush on our parent, since we need our container to be the
  // correct size to determine the correct style.
  if (StyleOrLayoutObservablyDependsOnParentDocumentLayout() &&
      IsSafeToFlush()) {
    mozilla::ChangesToFlush parentFlush = aFlush;
    if (flushType >= FlushType::Style) {
      parentFlush.mFlushType = std::max(FlushType::Layout, flushType);
    }
    mParentDocument->FlushPendingNotifications(parentFlush);
  }

  if (RefPtr<PresShell> presShell = GetPresShell()) {
    presShell->FlushPendingNotifications(aFlush);
  }
}

static bool Copy(Document* aDocument, void* aData) {
  auto* resources = static_cast<nsTArray<nsCOMPtr<Document>>*>(aData);
  resources->AppendElement(aDocument);
  return true;
}

void Document::FlushExternalResources(FlushType aType) {
  NS_ASSERTION(
      aType >= FlushType::Style,
      "should only need to flush for style or higher in external resources");
  if (GetDisplayDocument()) {
    return;
  }

  nsTArray<nsCOMPtr<Document>> resources;
  EnumerateExternalResources(Copy, &resources);

  for (uint32_t i = 0; i < resources.Length(); i++) {
    resources[i]->FlushPendingNotifications(aType);
  }
}

void Document::SetXMLDeclaration(const char16_t* aVersion,
                                 const char16_t* aEncoding,
                                 const int32_t aStandalone) {
  if (!aVersion || *aVersion == '\0') {
    mXMLDeclarationBits = 0;
    return;
  }

  mXMLDeclarationBits = XML_DECLARATION_BITS_DECLARATION_EXISTS;

  if (aEncoding && *aEncoding != '\0') {
    mXMLDeclarationBits |= XML_DECLARATION_BITS_ENCODING_EXISTS;
  }

  if (aStandalone == 1) {
    mXMLDeclarationBits |= XML_DECLARATION_BITS_STANDALONE_EXISTS |
                           XML_DECLARATION_BITS_STANDALONE_YES;
  } else if (aStandalone == 0) {
    mXMLDeclarationBits |= XML_DECLARATION_BITS_STANDALONE_EXISTS;
  }
}

void Document::GetXMLDeclaration(nsAString& aVersion, nsAString& aEncoding,
                                 nsAString& aStandalone) {
  aVersion.Truncate();
  aEncoding.Truncate();
  aStandalone.Truncate();

  if (!(mXMLDeclarationBits & XML_DECLARATION_BITS_DECLARATION_EXISTS)) {
    return;
  }

  // always until we start supporting 1.1 etc.
  aVersion.AssignLiteral("1.0");

  if (mXMLDeclarationBits & XML_DECLARATION_BITS_ENCODING_EXISTS) {
    // This is what we have stored, not necessarily what was written
    // in the original
    GetCharacterSet(aEncoding);
  }

  if (mXMLDeclarationBits & XML_DECLARATION_BITS_STANDALONE_EXISTS) {
    if (mXMLDeclarationBits & XML_DECLARATION_BITS_STANDALONE_YES) {
      aStandalone.AssignLiteral("yes");
    } else {
      aStandalone.AssignLiteral("no");
    }
  }
}

bool Document::IsScriptEnabled() {
  // If this document is sandboxed without 'allow-scripts'
  // script is not enabled
  if (HasScriptsBlockedBySandbox()) {
    return false;
  }

  nsCOMPtr<nsIScriptGlobalObject> globalObject =
      do_QueryInterface(GetInnerWindow());
  if (!globalObject || !globalObject->HasJSGlobal()) {
    return false;
  }

  return xpc::Scriptability::Get(globalObject->GetGlobalJSObjectPreserveColor())
      .Allowed();
}

void Document::RetrieveRelevantHeaders(nsIChannel* aChannel) {
  PRTime modDate = 0;
  nsresult rv;

  nsCOMPtr<nsIHttpChannel> httpChannel;
  rv = GetHttpChannelHelper(aChannel, getter_AddRefs(httpChannel));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return;
  }

  if (httpChannel) {
    nsAutoCString tmp;
    rv = httpChannel->GetResponseHeader(NS_LITERAL_CSTRING("last-modified"),
                                        tmp);

    if (NS_SUCCEEDED(rv)) {
      PRTime time;
      PRStatus st = PR_ParseTimeString(tmp.get(), true, &time);
      if (st == PR_SUCCESS) {
        modDate = time;
      }
    }

    // The misspelled key 'referer' is as per the HTTP spec
    rv =
        httpChannel->GetRequestHeader(NS_LITERAL_CSTRING("referer"), mReferrer);

    static const char* const headers[] = {
        "default-style", "content-style-type", "content-language",
        "content-disposition", "refresh", "x-dns-prefetch-control",
        "x-frame-options", "referrer-policy",
        // add more http headers if you need
        // XXXbz don't add content-location support without reading bug
        // 238654 and its dependencies/dups first.
        0};

    nsAutoCString headerVal;
    const char* const* name = headers;
    while (*name) {
      rv = httpChannel->GetResponseHeader(nsDependentCString(*name), headerVal);
      if (NS_SUCCEEDED(rv) && !headerVal.IsEmpty()) {
        RefPtr<nsAtom> key = NS_Atomize(*name);
        SetHeaderData(key, NS_ConvertASCIItoUTF16(headerVal));
      }
      ++name;
    }
  } else {
    nsCOMPtr<nsIFileChannel> fileChannel = do_QueryInterface(aChannel);
    if (fileChannel) {
      nsCOMPtr<nsIFile> file;
      fileChannel->GetFile(getter_AddRefs(file));
      if (file) {
        PRTime msecs;
        rv = file->GetLastModifiedTime(&msecs);

        if (NS_SUCCEEDED(rv)) {
          modDate = msecs * int64_t(PR_USEC_PER_MSEC);
        }
      }
    } else {
      nsAutoCString contentDisp;
      rv = aChannel->GetContentDispositionHeader(contentDisp);
      if (NS_SUCCEEDED(rv)) {
        SetHeaderData(nsGkAtoms::headerContentDisposition,
                      NS_ConvertASCIItoUTF16(contentDisp));
      }
    }
  }

  mLastModified.Truncate();
  if (modDate != 0) {
    GetFormattedTimeString(modDate, mLastModified);
  }
}

already_AddRefed<Element> Document::CreateElem(const nsAString& aName,
                                               nsAtom* aPrefix,
                                               int32_t aNamespaceID,
                                               const nsAString* aIs) {
#ifdef DEBUG
  nsAutoString qName;
  if (aPrefix) {
    aPrefix->ToString(qName);
    qName.Append(':');
  }
  qName.Append(aName);

  // Note: "a:b:c" is a valid name in non-namespaces XML, and
  // Document::CreateElement can call us with such a name and no prefix,
  // which would cause an error if we just used true here.
  bool nsAware = aPrefix != nullptr || aNamespaceID != GetDefaultNamespaceID();
  NS_ASSERTION(NS_SUCCEEDED(nsContentUtils::CheckQName(qName, nsAware)),
               "Don't pass invalid prefixes to Document::CreateElem, "
               "check caller.");
#endif

  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  mNodeInfoManager->GetNodeInfo(aName, aPrefix, aNamespaceID, ELEMENT_NODE,
                                getter_AddRefs(nodeInfo));
  NS_ENSURE_TRUE(nodeInfo, nullptr);

  nsCOMPtr<Element> element;
  nsresult rv = NS_NewElement(getter_AddRefs(element), nodeInfo.forget(),
                              NOT_FROM_PARSER, aIs);
  return NS_SUCCEEDED(rv) ? element.forget() : nullptr;
}

bool Document::IsSafeToFlush() const {
  PresShell* presShell = GetPresShell();
  if (!presShell) {
    return true;
  }
  return presShell->IsSafeToFlush();
}

void Document::Sanitize() {
  // Sanitize the document by resetting all (current and former) password fields
  // and any form fields with autocomplete=off to their default values.  We do
  // this now, instead of when the presentation is restored, to offer some
  // protection in case there is ever an exploit that allows a cached document
  // to be accessed from a different document.

  // First locate all input elements, regardless of whether they are
  // in a form, and reset the password and autocomplete=off elements.

  RefPtr<nsContentList> nodes =
      GetElementsByTagName(NS_LITERAL_STRING("input"));

  nsAutoString value;

  uint32_t length = nodes->Length(true);
  for (uint32_t i = 0; i < length; ++i) {
    NS_ASSERTION(nodes->Item(i), "null item in node list!");

    RefPtr<HTMLInputElement> input =
        HTMLInputElement::FromNodeOrNull(nodes->Item(i));
    if (!input) continue;

    input->GetAttribute(NS_LITERAL_STRING("autocomplete"), value);
    if (value.LowerCaseEqualsLiteral("off") || input->HasBeenTypePassword()) {
      input->Reset();
    }
  }

  // Now locate all _form_ elements that have autocomplete=off and reset them
  nodes = GetElementsByTagName(NS_LITERAL_STRING("form"));

  length = nodes->Length(true);
  for (uint32_t i = 0; i < length; ++i) {
    NS_ASSERTION(nodes->Item(i), "null item in nodelist");

    HTMLFormElement* form = HTMLFormElement::FromNode(nodes->Item(i));
    if (!form) continue;

    form->GetAttr(kNameSpaceID_None, nsGkAtoms::autocomplete, value);
    if (value.LowerCaseEqualsLiteral("off")) form->Reset();
  }
}

void Document::EnumerateSubDocuments(SubDocEnumFunc aCallback, void* aData) {
  if (!mSubDocuments) {
    return;
  }

  // PLDHashTable::Iterator can't handle modifications while iterating so we
  // copy all entries to an array first before calling any callbacks.
  AutoTArray<nsCOMPtr<Document>, 8> subdocs;
  for (auto iter = mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
    auto entry = static_cast<SubDocMapEntry*>(iter.Get());
    Document* subdoc = entry->mSubDocument;
    if (subdoc) {
      subdocs.AppendElement(subdoc);
    }
  }
  for (auto subdoc : subdocs) {
    if (!aCallback(subdoc, aData)) {
      break;
    }
  }
}

void Document::CollectDescendantDocuments(
    nsTArray<RefPtr<Document>>& aDescendants, nsDocTestFunc aCallback) const {
  if (!mSubDocuments) {
    return;
  }

  for (auto iter = mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
    auto entry = static_cast<SubDocMapEntry*>(iter.Get());
    const Document* subdoc = entry->mSubDocument;
    if (subdoc) {
      if (aCallback(subdoc)) {
        aDescendants.AppendElement(entry->mSubDocument);
      }
      subdoc->CollectDescendantDocuments(aDescendants, aCallback);
    }
  }
}

bool Document::CanSavePresentation(nsIRequest* aNewRequest,
                                   uint16_t& aBFCacheCombo) {
  bool ret = true;

  if (!IsBFCachingAllowed()) {
    aBFCacheCombo |= BFCacheStatus::NOT_ALLOWED;
    ret = false;
  }

  nsAutoCString uri;
  if (MOZ_UNLIKELY(MOZ_LOG_TEST(gPageCacheLog, LogLevel::Verbose))) {
    if (mDocumentURI) {
      mDocumentURI->GetSpec(uri);
    }
  }

  if (EventHandlingSuppressed()) {
    MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
            ("Save of %s blocked on event handling suppression", uri.get()));
    aBFCacheCombo |= BFCacheStatus::EVENT_HANDLING_SUPPRESSED;
    ret = false;
  }

  // Do not allow suspended windows to be placed in the
  // bfcache.  This method is also used to verify a document
  // coming out of the bfcache is ok to restore, though.  So
  // we only want to block suspend windows that aren't also
  // frozen.
  nsPIDOMWindowInner* win = GetInnerWindow();
  if (win && win->IsSuspended() && !win->IsFrozen()) {
    MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
            ("Save of %s blocked on suspended Window", uri.get()));
    aBFCacheCombo |= BFCacheStatus::SUSPENDED;
    ret = false;
  }

  // Check our event listener manager for unload/beforeunload listeners.
  nsCOMPtr<EventTarget> piTarget = do_QueryInterface(mScriptGlobalObject);
  if (piTarget) {
    EventListenerManager* manager = piTarget->GetExistingListenerManager();
    if (manager && manager->HasUnloadListeners()) {
      MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
              ("Save of %s blocked due to unload handlers", uri.get()));
      aBFCacheCombo |= BFCacheStatus::UNLOAD_LISTENER;
      ret = false;
    }
  }

  // Check if we have pending network requests
  nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
  if (loadGroup) {
    nsCOMPtr<nsISimpleEnumerator> requests;
    loadGroup->GetRequests(getter_AddRefs(requests));

    bool hasMore = false;

    // We want to bail out if we have any requests other than aNewRequest (or
    // in the case when aNewRequest is a part of a multipart response the base
    // channel the multipart response is coming in on).
    nsCOMPtr<nsIChannel> baseChannel;
    nsCOMPtr<nsIMultiPartChannel> part(do_QueryInterface(aNewRequest));
    if (part) {
      part->GetBaseChannel(getter_AddRefs(baseChannel));
    }

    while (NS_SUCCEEDED(requests->HasMoreElements(&hasMore)) && hasMore) {
      nsCOMPtr<nsISupports> elem;
      requests->GetNext(getter_AddRefs(elem));

      nsCOMPtr<nsIRequest> request = do_QueryInterface(elem);
      if (request && request != aNewRequest && request != baseChannel) {
        // Favicon loads don't need to block caching.
        nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
        if (channel) {
          nsCOMPtr<nsILoadInfo> li = channel->LoadInfo();
          if (li->InternalContentPolicyType() ==
              nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON) {
            continue;
          }
        }

        if (MOZ_UNLIKELY(MOZ_LOG_TEST(gPageCacheLog, LogLevel::Verbose))) {
          nsAutoCString requestName;
          request->GetName(requestName);
          MOZ_LOG(gPageCacheLog, LogLevel::Verbose,
                  ("Save of %s blocked because document has request %s",
                   uri.get(), requestName.get()));
        }
        aBFCacheCombo |= BFCacheStatus::REQUEST;
        ret = false;
      }
    }
  }

  // Check if we have active GetUserMedia use
  if (MediaManager::Exists() && win &&
      MediaManager::Get()->IsWindowStillActive(win->WindowID())) {
    MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
            ("Save of %s blocked due to GetUserMedia", uri.get()));
    aBFCacheCombo |= BFCacheStatus::ACTIVE_GET_USER_MEDIA;
    ret = false;
  }

#ifdef MOZ_WEBRTC
  // Check if we have active PeerConnections
  if (win && win->HasActivePeerConnections()) {
    MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
            ("Save of %s blocked due to PeerConnection", uri.get()));
    aBFCacheCombo |= BFCacheStatus::ACTIVE_PEER_CONNECTION;
    ret = false;
  }
#endif  // MOZ_WEBRTC

  // Don't save presentations for documents containing EME content, so that
  // CDMs reliably shutdown upon user navigation.
  if (ContainsEMEContent()) {
    aBFCacheCombo |= BFCacheStatus::CONTAINS_EME_CONTENT;
    ret = false;
  }

  // Don't save presentations for documents containing MSE content, to
  // reduce memory usage.
  if (ContainsMSEContent()) {
    MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
            ("Save of %s blocked due to MSE use", uri.get()));
    aBFCacheCombo |= BFCacheStatus::CONTAINS_MSE_CONTENT;
    ret = false;
  }

  if (mSubDocuments) {
    for (auto iter = mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
      auto entry = static_cast<SubDocMapEntry*>(iter.Get());
      Document* subdoc = entry->mSubDocument;

      uint16_t subDocBFCacheCombo = 0;
      // The aIgnoreRequest we were passed is only for us, so don't pass it on.
      bool canCache =
          subdoc ? subdoc->CanSavePresentation(nullptr, subDocBFCacheCombo)
                 : false;
      if (!canCache) {
        MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
                ("Save of %s blocked due to subdocument blocked", uri.get()));
        aBFCacheCombo |= subDocBFCacheCombo;
        ret = false;
      }
    }
  }

  if (win) {
    auto* globalWindow = nsGlobalWindowInner::Cast(win);
#ifdef MOZ_WEBSPEECH
    if (globalWindow->HasActiveSpeechSynthesis()) {
      MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
              ("Save of %s blocked due to Speech use", uri.get()));
      aBFCacheCombo |= BFCacheStatus::HAS_ACTIVE_SPEECH_SYNTHESIS;
      ret = false;
    }
#endif
    if (globalWindow->HasUsedVR()) {
      MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
              ("Save of %s blocked due to having used VR", uri.get()));
      aBFCacheCombo |= BFCacheStatus::HAS_USED_VR;
      ret = false;
    }
  }

  return ret;
}

void Document::Destroy() {
  // The ContentViewer wants to release the document now.  So, tell our content
  // to drop any references to the document so that it can be destroyed.
  if (mIsGoingAway) return;

  // Make sure to report before IPC closed.
  if (!nsContentUtils::IsInPrivateBrowsing(this)) {
    mContentBlockingLog.ReportLog();
  }

  mIsGoingAway = true;

  if (mDocumentL10n) {
    mDocumentL10n->Destroy();
  }

  ScriptLoader()->Destroy();
  SetScriptGlobalObject(nullptr);
  RemovedFromDocShell();

  bool oldVal = mInUnlinkOrDeletion;
  mInUnlinkOrDeletion = true;

#ifdef DEBUG
  uint32_t oldChildCount = GetChildCount();
#endif

  for (nsIContent* child = GetFirstChild(); child;
       child = child->GetNextSibling()) {
    child->DestroyContent();
    MOZ_ASSERT(child->GetParentNode() == this);
  }
  MOZ_ASSERT(oldChildCount == GetChildCount());

  mInUnlinkOrDeletion = oldVal;

  mLayoutHistoryState = nullptr;

  if (mOriginalDocument) {
    mOriginalDocument->mLatestStaticClone = nullptr;
  }

  // Shut down our external resource map.  We might not need this for
  // leak-fixing if we fix nsDocumentViewer to do cycle-collection, but
  // tearing down all those frame trees right now is the right thing to do.
  mExternalResourceMap.Shutdown();
}

void Document::RemovedFromDocShell() {
  if (mRemovedFromDocShell) return;

  mRemovedFromDocShell = true;
  EnumerateActivityObservers(NotifyActivityChanged, nullptr);

  for (nsIContent* child = GetFirstChild(); child;
       child = child->GetNextSibling()) {
    child->SaveSubtreeState();
  }
}

already_AddRefed<nsILayoutHistoryState> Document::GetLayoutHistoryState()
    const {
  nsCOMPtr<nsILayoutHistoryState> state;
  if (!mScriptGlobalObject) {
    state = mLayoutHistoryState;
  } else {
    nsCOMPtr<nsIDocShell> docShell(mDocumentContainer);
    if (docShell) {
      docShell->GetLayoutHistoryState(getter_AddRefs(state));
    }
  }

  return state.forget();
}

void Document::EnsureOnloadBlocker() {
  // If mScriptGlobalObject is null, we shouldn't be messing with the loadgroup
  // -- it's not ours.
  if (mOnloadBlockCount != 0 && mScriptGlobalObject) {
    nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
    if (loadGroup) {
      // Check first to see if mOnloadBlocker is in the loadgroup.
      nsCOMPtr<nsISimpleEnumerator> requests;
      loadGroup->GetRequests(getter_AddRefs(requests));

      bool hasMore = false;
      while (NS_SUCCEEDED(requests->HasMoreElements(&hasMore)) && hasMore) {
        nsCOMPtr<nsISupports> elem;
        requests->GetNext(getter_AddRefs(elem));
        nsCOMPtr<nsIRequest> request = do_QueryInterface(elem);
        if (request && request == mOnloadBlocker) {
          return;
        }
      }

      // Not in the loadgroup, so add it.
      loadGroup->AddRequest(mOnloadBlocker, nullptr);
    }
  }
}

void Document::AsyncBlockOnload() {
  while (mAsyncOnloadBlockCount) {
    --mAsyncOnloadBlockCount;
    BlockOnload();
  }
}

void Document::BlockOnload() {
  if (mDisplayDocument) {
    mDisplayDocument->BlockOnload();
    return;
  }

  // If mScriptGlobalObject is null, we shouldn't be messing with the loadgroup
  // -- it's not ours.
  if (mOnloadBlockCount == 0 && mScriptGlobalObject) {
    if (!nsContentUtils::IsSafeToRunScript()) {
      // Because AddRequest may lead to OnStateChange calls in chrome,
      // block onload only when there are no script blockers.
      ++mAsyncOnloadBlockCount;
      if (mAsyncOnloadBlockCount == 1) {
        nsContentUtils::AddScriptRunner(NewRunnableMethod(
            "Document::AsyncBlockOnload", this, &Document::AsyncBlockOnload));
      }
      return;
    }
    nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
    if (loadGroup) {
      loadGroup->AddRequest(mOnloadBlocker, nullptr);
    }
  }
  ++mOnloadBlockCount;
}

void Document::UnblockOnload(bool aFireSync) {
  if (mDisplayDocument) {
    mDisplayDocument->UnblockOnload(aFireSync);
    return;
  }

  if (mOnloadBlockCount == 0 && mAsyncOnloadBlockCount == 0) {
    MOZ_ASSERT_UNREACHABLE(
        "More UnblockOnload() calls than BlockOnload() "
        "calls; dropping call");
    return;
  }

  --mOnloadBlockCount;

  if (mOnloadBlockCount == 0) {
    if (mScriptGlobalObject) {
      // Only manipulate the loadgroup in this case, because if
      // mScriptGlobalObject is null, it's not ours.
      if (aFireSync && mAsyncOnloadBlockCount == 0) {
        // Increment mOnloadBlockCount, since DoUnblockOnload will decrement it
        ++mOnloadBlockCount;
        DoUnblockOnload();
      } else {
        PostUnblockOnloadEvent();
      }
    } else if (mIsBeingUsedAsImage) {
      // To correctly unblock onload for a document that contains an SVG
      // image, we need to know when all of the SVG document's resources are
      // done loading, in a way comparable to |window.onload|. We fire this
      // event to indicate that the SVG should be considered fully loaded.
      // Because scripting is disabled on SVG-as-image documents, this event
      // is not accessible to content authors. (See bug 837315.)
      RefPtr<AsyncEventDispatcher> asyncDispatcher = new AsyncEventDispatcher(
          this, NS_LITERAL_STRING("MozSVGAsImageDocumentLoad"), CanBubble::eNo,
          ChromeOnlyDispatch::eNo);
      asyncDispatcher->PostDOMEvent();
    }
  }
}

class nsUnblockOnloadEvent : public Runnable {
 public:
  explicit nsUnblockOnloadEvent(Document* aDoc)
      : mozilla::Runnable("nsUnblockOnloadEvent"), mDoc(aDoc) {}
  NS_IMETHOD Run() override {
    mDoc->DoUnblockOnload();
    return NS_OK;
  }

 private:
  RefPtr<Document> mDoc;
};

void Document::PostUnblockOnloadEvent() {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  nsCOMPtr<nsIRunnable> evt = new nsUnblockOnloadEvent(this);
  nsresult rv = Dispatch(TaskCategory::Other, evt.forget());
  if (NS_SUCCEEDED(rv)) {
    // Stabilize block count so we don't post more events while this one is up
    ++mOnloadBlockCount;
  } else {
    NS_WARNING("failed to dispatch nsUnblockOnloadEvent");
  }
}

void Document::DoUnblockOnload() {
  MOZ_ASSERT(!mDisplayDocument, "Shouldn't get here for resource document");
  MOZ_ASSERT(mOnloadBlockCount != 0,
             "Shouldn't have a count of zero here, since we stabilized in "
             "PostUnblockOnloadEvent");

  --mOnloadBlockCount;

  if (mOnloadBlockCount != 0) {
    // We blocked again after the last unblock.  Nothing to do here.  We'll
    // post a new event when we unblock again.
    return;
  }

  if (mAsyncOnloadBlockCount != 0) {
    // We need to wait until the async onload block has been handled.
    PostUnblockOnloadEvent();
  }

  // If mScriptGlobalObject is null, we shouldn't be messing with the loadgroup
  // -- it's not ours.
  if (mScriptGlobalObject) {
    nsCOMPtr<nsILoadGroup> loadGroup = GetDocumentLoadGroup();
    if (loadGroup) {
      loadGroup->RemoveRequest(mOnloadBlocker, nullptr, NS_OK);
    }
  }
}

nsIContent* Document::GetContentInThisDocument(nsIFrame* aFrame) const {
  for (nsIFrame* f = aFrame; f;
       f = nsLayoutUtils::GetParentOrPlaceholderForCrossDoc(f)) {
    nsIContent* content = f->GetContent();
    if (!content || content->IsInAnonymousSubtree()) continue;

    if (content->OwnerDoc() == this) {
      return content;
    }
    // We must be in a subdocument so jump directly to the root frame.
    // GetParentOrPlaceholderForCrossDoc gets called immediately to jump up to
    // the containing document.
    f = f->PresContext()->GetPresShell()->GetRootFrame();
  }

  return nullptr;
}

void Document::DispatchPageTransition(EventTarget* aDispatchTarget,
                                      const nsAString& aType, bool aPersisted,
                                      bool aOnlySystemGroup) {
  if (!aDispatchTarget) {
    return;
  }

  PageTransitionEventInit init;
  init.mBubbles = true;
  init.mCancelable = true;
  init.mPersisted = aPersisted;

  nsDocShell* docShell = mDocumentContainer.get();
  init.mInFrameSwap = docShell && docShell->InFrameSwap();

  RefPtr<PageTransitionEvent> event =
      PageTransitionEvent::Constructor(this, aType, init);

  event->SetTrusted(true);
  event->SetTarget(this);
  if (aOnlySystemGroup) {
    event->WidgetEventPtr()->mFlags.mOnlySystemGroupDispatchInContent = true;
  }
  EventDispatcher::DispatchDOMEvent(aDispatchTarget, nullptr, event, nullptr,
                                    nullptr);
}

static bool NotifyPageShow(Document* aDocument, void* aData) {
  const bool* aPersistedPtr = static_cast<const bool*>(aData);
  aDocument->OnPageShow(*aPersistedPtr, nullptr);
  return true;
}

void Document::OnPageShow(bool aPersisted, EventTarget* aDispatchStartTarget,
                          bool aOnlySystemGroup) {
  mVisible = true;

  EnumerateActivityObservers(NotifyActivityChanged, nullptr);
  EnumerateExternalResources(NotifyPageShow, &aPersisted);

  Element* root = GetRootElement();
  if (aPersisted && root) {
    // Send out notifications that our <link> elements are attached.
    RefPtr<nsContentList> links =
        NS_GetContentList(root, kNameSpaceID_XHTML, NS_LITERAL_STRING("link"));

    uint32_t linkCount = links->Length(true);
    for (uint32_t i = 0; i < linkCount; ++i) {
      static_cast<HTMLLinkElement*>(links->Item(i, false))->LinkAdded();
    }
  }

  // See Document
  if (!aDispatchStartTarget) {
    // Set mIsShowing before firing events, in case those event handlers
    // move us around.
    mIsShowing = true;
  }

  if (mAnimationController) {
    mAnimationController->OnPageShow();
  }

  if (aPersisted) {
    ImageTracker()->SetAnimatingState(true);
  }

  UpdateVisibilityState();

  if (!mIsBeingUsedAsImage) {
    // Dispatch observer notification to notify observers page is shown.
    nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
    if (os) {
      nsIPrincipal* principal = NodePrincipal();
      os->NotifyObservers(ToSupports(this),
                          nsContentUtils::IsSystemPrincipal(principal)
                              ? "chrome-page-shown"
                              : "content-page-shown",
                          nullptr);
    }

    nsCOMPtr<EventTarget> target = aDispatchStartTarget;
    if (!target) {
      target = do_QueryInterface(GetWindow());
    }
    DispatchPageTransition(target, NS_LITERAL_STRING("pageshow"), aPersisted,
                           aOnlySystemGroup);
  }
}

static bool NotifyPageHide(Document* aDocument, void* aData) {
  const bool* aPersistedPtr = static_cast<const bool*>(aData);
  aDocument->OnPageHide(*aPersistedPtr, nullptr);
  return true;
}

static void DispatchFullscreenChange(Document* aDocument, nsINode* aTarget) {
  if (nsPresContext* presContext = aDocument->GetPresContext()) {
    auto pendingEvent = MakeUnique<PendingFullscreenEvent>(
        FullscreenEventType::Change, aDocument, aTarget);
    presContext->RefreshDriver()->ScheduleFullscreenEvent(
        std::move(pendingEvent));
  }
}

static void ClearPendingFullscreenRequests(Document* aDoc);

static bool HasHttpScheme(nsIURI* aURI) {
  bool isHttpish = false;
  return aURI &&
         ((NS_SUCCEEDED(aURI->SchemeIs("http", &isHttpish)) && isHttpish) ||
          (NS_SUCCEEDED(aURI->SchemeIs("https", &isHttpish)) && isHttpish));
}

void Document::OnPageHide(bool aPersisted, EventTarget* aDispatchStartTarget,
                          bool aOnlySystemGroup) {
  if (IsTopLevelContentDocument() && GetDocGroup() &&
      Telemetry::CanRecordExtended()) {
    TabGroup* tabGroup = mDocGroup->GetTabGroup();

    if (tabGroup) {
      uint32_t active = tabGroup->Count(true /* aActiveOnly */);
      uint32_t total = tabGroup->Count();

      if (HasHttpScheme(GetDocumentURI())) {
        Telemetry::Accumulate(Telemetry::ACTIVE_HTTP_DOCGROUPS_PER_TABGROUP,
                              active);
        Telemetry::Accumulate(Telemetry::TOTAL_HTTP_DOCGROUPS_PER_TABGROUP,
                              total);
      }
    }
  }

  // Send out notifications that our <link> elements are detached,
  // but only if this is not a full unload.
  Element* root = GetRootElement();
  if (aPersisted && root) {
    RefPtr<nsContentList> links =
        NS_GetContentList(root, kNameSpaceID_XHTML, NS_LITERAL_STRING("link"));

    uint32_t linkCount = links->Length(true);
    for (uint32_t i = 0; i < linkCount; ++i) {
      static_cast<HTMLLinkElement*>(links->Item(i, false))->LinkRemoved();
    }
  }

  // See Document
  if (!aDispatchStartTarget) {
    // Set mIsShowing before firing events, in case those event handlers
    // move us around.
    mIsShowing = false;
  }

  if (mAnimationController) {
    mAnimationController->OnPageHide();
  }

  // We do not stop the animations (bug 1024343)
  // when the page is refreshing while being dragged out
  nsDocShell* docShell = mDocumentContainer.get();
  if (aPersisted && !(docShell && docShell->InFrameSwap())) {
    ImageTracker()->SetAnimatingState(false);
  }

  ExitPointerLock();

  if (!mIsBeingUsedAsImage) {
    // Dispatch observer notification to notify observers page is hidden.
    nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
    if (os) {
      nsIPrincipal* principal = NodePrincipal();
      os->NotifyObservers(ToSupports(this),
                          nsContentUtils::IsSystemPrincipal(principal)
                              ? "chrome-page-hidden"
                              : "content-page-hidden",
                          nullptr);
    }

    // Now send out a PageHide event.
    nsCOMPtr<EventTarget> target = aDispatchStartTarget;
    if (!target) {
      target = do_QueryInterface(GetWindow());
    }
    {
      PageUnloadingEventTimeStamp timeStamp(this);
      DispatchPageTransition(target, NS_LITERAL_STRING("pagehide"), aPersisted,
                             aOnlySystemGroup);
    }
  }

  mVisible = false;

  UpdateVisibilityState();

  EnumerateExternalResources(NotifyPageHide, &aPersisted);
  EnumerateActivityObservers(NotifyActivityChanged, nullptr);

  ClearPendingFullscreenRequests(this);
  if (FullscreenStackTop()) {
    // If this document was fullscreen, we should exit fullscreen in this
    // doctree branch. This ensures that if the user navigates while in
    // fullscreen mode we don't leave its still visible ancestor documents
    // in fullscreen mode. So exit fullscreen in the document's fullscreen
    // root document, as this will exit fullscreen in all the root's
    // descendant documents. Note that documents are removed from the
    // doctree by the time OnPageHide() is called, so we must store a
    // reference to the root (in Document::mFullscreenRoot) since we can't
    // just traverse the doctree to get the root.
    Document::ExitFullscreenInDocTree(this);

    // Since the document is removed from the doctree before OnPageHide() is
    // called, ExitFullscreen() can't traverse from the root down to *this*
    // document, so we must manually call CleanupFullscreenState() below too.
    // Note that CleanupFullscreenState() clears Document::mFullscreenRoot,
    // so we *must* call it after ExitFullscreen(), not before.
    // OnPageHide() is called in every hidden (i.e. descendant) document,
    // so calling CleanupFullscreenState() here will ensure all hidden
    // documents have their fullscreen state reset.
    CleanupFullscreenState();

    // The fullscreenchange event is to be queued in the refresh driver,
    // however a hidden page wouldn't trigger that again, so it makes no
    // sense to dispatch such event here.
  }
}

void Document::WillDispatchMutationEvent(nsINode* aTarget) {
  NS_ASSERTION(
      mSubtreeModifiedDepth != 0 || mSubtreeModifiedTargets.Count() == 0,
      "mSubtreeModifiedTargets not cleared after dispatching?");
  ++mSubtreeModifiedDepth;
  if (aTarget) {
    // MayDispatchMutationEvent is often called just before this method,
    // so it has already appended the node to mSubtreeModifiedTargets.
    int32_t count = mSubtreeModifiedTargets.Count();
    if (!count || mSubtreeModifiedTargets[count - 1] != aTarget) {
      mSubtreeModifiedTargets.AppendObject(aTarget);
    }
  }
}

void Document::MutationEventDispatched(nsINode* aTarget) {
  --mSubtreeModifiedDepth;
  if (mSubtreeModifiedDepth == 0) {
    int32_t count = mSubtreeModifiedTargets.Count();
    if (!count) {
      return;
    }

    nsPIDOMWindowInner* window = GetInnerWindow();
    if (window &&
        !window->HasMutationListeners(NS_EVENT_BITS_MUTATION_SUBTREEMODIFIED)) {
      mSubtreeModifiedTargets.Clear();
      return;
    }

    nsCOMArray<nsINode> realTargets;
    for (int32_t i = 0; i < count; ++i) {
      nsINode* possibleTarget = mSubtreeModifiedTargets[i];
      nsCOMPtr<nsIContent> content = do_QueryInterface(possibleTarget);
      if (content && content->ChromeOnlyAccess()) {
        continue;
      }

      nsINode* commonAncestor = nullptr;
      int32_t realTargetCount = realTargets.Count();
      for (int32_t j = 0; j < realTargetCount; ++j) {
        commonAncestor =
            nsContentUtils::GetCommonAncestor(possibleTarget, realTargets[j]);
        if (commonAncestor) {
          realTargets.ReplaceObjectAt(commonAncestor, j);
          break;
        }
      }
      if (!commonAncestor) {
        realTargets.AppendObject(possibleTarget);
      }
    }

    mSubtreeModifiedTargets.Clear();

    int32_t realTargetCount = realTargets.Count();
    for (int32_t k = 0; k < realTargetCount; ++k) {
      InternalMutationEvent mutation(true, eLegacySubtreeModified);
      (new AsyncEventDispatcher(realTargets[k], mutation))
          ->RunDOMEventWhenSafe();
    }
  }
}

void Document::DestroyElementMaps() {
#ifdef DEBUG
  mStyledLinksCleared = true;
#endif
  mStyledLinks.Clear();
  mIdentifierMap.Clear();
  mComposedShadowRoots.Clear();
  mResponsiveContent.Clear();
  IncrementExpandoGeneration(*this);
}

void Document::RefreshLinkHrefs() {
  // Get a list of all links we know about.  We will reset them, which will
  // remove them from the document, so we need a copy of what is in the
  // hashtable.
  LinkArray linksToNotify(mStyledLinks.Count());
  for (auto iter = mStyledLinks.ConstIter(); !iter.Done(); iter.Next()) {
    linksToNotify.AppendElement(iter.Get()->GetKey());
  }

  // Reset all of our styled links.
  nsAutoScriptBlocker scriptBlocker;
  for (LinkArray::size_type i = 0; i < linksToNotify.Length(); i++) {
    linksToNotify[i]->ResetLinkState(true, linksToNotify[i]->ElementHasHref());
  }
}

nsresult Document::CloneDocHelper(Document* clone) const {
  clone->mIsStaticDocument = mCreatingStaticClone;

  // Init document
  nsresult rv = clone->Init();
  NS_ENSURE_SUCCESS(rv, rv);

  if (mCreatingStaticClone) {
    nsCOMPtr<nsILoadGroup> loadGroup;

    // |mDocumentContainer| is the container of the document that is being
    // created and not the original container. See CreateStaticClone function().
    nsCOMPtr<nsIDocumentLoader> docLoader(mDocumentContainer);
    if (docLoader) {
      docLoader->GetLoadGroup(getter_AddRefs(loadGroup));
    }
    nsCOMPtr<nsIChannel> channel = GetChannel();
    nsCOMPtr<nsIURI> uri;
    if (channel) {
      NS_GetFinalChannelURI(channel, getter_AddRefs(uri));
    } else {
      uri = Document::GetDocumentURI();
    }
    clone->mChannel = channel;
    if (uri) {
      clone->ResetToURI(uri, loadGroup, NodePrincipal(),
                        EffectiveStoragePrincipal());
    }

    clone->SetContainer(mDocumentContainer);
  }

  // Now ensure that our clone has the same URI, base URI, and principal as us.
  // We do this after the mCreatingStaticClone block above, because that block
  // can set the base URI to an incorrect value in cases when base URI
  // information came from the channel.  So we override explicitly, and do it
  // for all these properties, in case ResetToURI messes with any of the rest of
  // them.
  clone->SetDocumentURI(Document::GetDocumentURI());
  clone->SetChromeXHRDocURI(mChromeXHRDocURI);
  clone->SetPrincipals(NodePrincipal(), EffectiveStoragePrincipal());
  clone->mDocumentBaseURI = mDocumentBaseURI;
  clone->SetChromeXHRDocBaseURI(mChromeXHRDocBaseURI);

  bool hasHadScriptObject = true;
  nsIScriptGlobalObject* scriptObject =
      GetScriptHandlingObject(hasHadScriptObject);
  NS_ENSURE_STATE(scriptObject || !hasHadScriptObject);
  if (mCreatingStaticClone) {
    // If we're doing a static clone (print, print preview), then we're going to
    // be setting a scope object after the clone. It's better to set it only
    // once, so we don't do that here. However, we do want to act as if there is
    // a script handling object. So we set mHasHadScriptHandlingObject.
    clone->mHasHadScriptHandlingObject = true;
  } else if (scriptObject) {
    clone->SetScriptHandlingObject(scriptObject);
  } else {
    clone->SetScopeObject(GetScopeObject());
  }
  // Make the clone a data document
  clone->SetLoadedAsData(true);

  // Misc state

  // State from Document
  clone->mCharacterSet = mCharacterSet;
  clone->mCharacterSetSource = mCharacterSetSource;
  clone->mCompatMode = mCompatMode;
  clone->mBidiOptions = mBidiOptions;
  clone->mContentLanguage = mContentLanguage;
  clone->SetContentTypeInternal(GetContentTypeInternal());
  clone->mSecurityInfo = mSecurityInfo;

  // State from Document
  clone->mType = mType;
  clone->mXMLDeclarationBits = mXMLDeclarationBits;
  clone->mBaseTarget = mBaseTarget;

  return NS_OK;
}

static bool SetLoadingInSubDocument(Document* aDocument, void* aData) {
  aDocument->SetAncestorLoading(*(static_cast<bool*>(aData)));
  return true;
}

void Document::SetAncestorLoading(bool aAncestorIsLoading) {
  NotifyLoading(mAncestorIsLoading, aAncestorIsLoading, mReadyState,
                mReadyState);
  mAncestorIsLoading = aAncestorIsLoading;
}

void Document::NotifyLoading(const bool& aCurrentParentIsLoading,
                             bool aNewParentIsLoading,
                             const ReadyState& aCurrentState,
                             ReadyState aNewState) {
  // Mirror the top-level loading state down to all subdocuments
  bool was_loading = aCurrentParentIsLoading ||
                     aCurrentState == READYSTATE_LOADING ||
                     aCurrentState == READYSTATE_INTERACTIVE;
  bool is_loading = aNewParentIsLoading || aNewState == READYSTATE_LOADING ||
                    aNewState == READYSTATE_INTERACTIVE;  // new value for state
  bool set_load_state = was_loading != is_loading;

  if (set_load_state && StaticPrefs::dom_timeout_defer_during_load()) {
    nsPIDOMWindowInner* inner = GetInnerWindow();
    if (inner) {
      inner->SetActiveLoadingState(is_loading);
    }
    EnumerateSubDocuments(SetLoadingInSubDocument, &is_loading);
  }
}

void Document::SetReadyStateInternal(ReadyState rs,
                                     bool updateTimingInformation) {
  if (rs == READYSTATE_UNINITIALIZED) {
    // Transition back to uninitialized happens only to keep assertions happy
    // right before readyState transitions to something else. Make this
    // transition undetectable by Web content.
    mReadyState = rs;
    return;
  }

  if (updateTimingInformation && READYSTATE_LOADING == rs) {
    mLoadingTimeStamp = mozilla::TimeStamp::Now();
  }
  NotifyLoading(mAncestorIsLoading, mAncestorIsLoading, mReadyState, rs);
  mReadyState = rs;
  if (updateTimingInformation && mTiming) {
    switch (rs) {
      case READYSTATE_LOADING:
        mTiming->NotifyDOMLoading(Document::GetDocumentURI());
        break;
      case READYSTATE_INTERACTIVE:
        mTiming->NotifyDOMInteractive(Document::GetDocumentURI());
        break;
      case READYSTATE_COMPLETE:
        mTiming->NotifyDOMComplete(Document::GetDocumentURI());
        break;
      default:
        NS_WARNING("Unexpected ReadyState value");
        break;
    }
  }
  // At the time of loading start, we don't have timing object, record time.

  if (READYSTATE_INTERACTIVE == rs) {
    if (nsContentUtils::IsSystemPrincipal(NodePrincipal())) {
      Element* root = GetRootElement();
      if ((root && root->HasAttr(kNameSpaceID_None, nsGkAtoms::mozpersist)) ||
          IsXULDocument()) {
        mXULPersist = new XULPersist(this);
        mXULPersist->Init();
      }
    }
  }

  if (updateTimingInformation) {
    RecordNavigationTiming(rs);
  }

  RefPtr<AsyncEventDispatcher> asyncDispatcher =
      new AsyncEventDispatcher(this, NS_LITERAL_STRING("readystatechange"),
                               CanBubble::eNo, ChromeOnlyDispatch::eNo);
  asyncDispatcher->RunDOMEventWhenSafe();
}

void Document::GetReadyState(nsAString& aReadyState) const {
  switch (mReadyState) {
    case READYSTATE_LOADING:
      aReadyState.AssignLiteral(u"loading");
      break;
    case READYSTATE_INTERACTIVE:
      aReadyState.AssignLiteral(u"interactive");
      break;
    case READYSTATE_COMPLETE:
      aReadyState.AssignLiteral(u"complete");
      break;
    default:
      aReadyState.AssignLiteral(u"uninitialized");
  }
}

static bool SuppressEventHandlingInDocument(Document* aDocument, void* aData) {
  aDocument->SuppressEventHandling(*static_cast<uint32_t*>(aData));

  return true;
}

void Document::SuppressEventHandling(uint32_t aIncrease) {
  mEventsSuppressed += aIncrease;
  UpdateFrameRequestCallbackSchedulingState();
  for (uint32_t i = 0; i < aIncrease; ++i) {
    ScriptLoader()->AddExecuteBlocker();
  }

  EnumerateSubDocuments(SuppressEventHandlingInDocument, &aIncrease);
}

static void FireOrClearDelayedEvents(nsTArray<nsCOMPtr<Document>>& aDocuments,
                                     bool aFireEvents) {
  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  if (!fm) return;

  for (uint32_t i = 0; i < aDocuments.Length(); ++i) {
    // NB: Don't bother trying to fire delayed events on documents that were
    // closed before this event ran.
    if (!aDocuments[i]->EventHandlingSuppressed()) {
      fm->FireDelayedEvents(aDocuments[i]);
      RefPtr<PresShell> presShell = aDocuments[i]->GetPresShell();
      if (presShell) {
        // Only fire events for active documents.
        bool fire = aFireEvents && aDocuments[i]->GetInnerWindow() &&
                    aDocuments[i]->GetInnerWindow()->IsCurrentInnerWindow();
        presShell->FireOrClearDelayedEvents(fire);
      }
    }
  }
}

void Document::PreloadPictureClosed() {
  MOZ_ASSERT(mPreloadPictureDepth > 0);
  mPreloadPictureDepth--;
  if (mPreloadPictureDepth == 0) {
    mPreloadPictureFoundSource.SetIsVoid(true);
  }
}

void Document::PreloadPictureImageSource(const nsAString& aSrcsetAttr,
                                         const nsAString& aSizesAttr,
                                         const nsAString& aTypeAttr,
                                         const nsAString& aMediaAttr) {
  // Nested pictures are not valid syntax, so while we'll eventually load them,
  // it's not worth tracking sources mixed between nesting levels to preload
  // them effectively.
  if (mPreloadPictureDepth == 1 && mPreloadPictureFoundSource.IsVoid()) {
    // <picture> selects the first matching source, so if this returns a URI we
    // needn't consider new sources until a new <picture> is encountered.
    bool found = HTMLImageElement::SelectSourceForTagWithAttrs(
        this, true, VoidString(), aSrcsetAttr, aSizesAttr, aTypeAttr,
        aMediaAttr, mPreloadPictureFoundSource);
    if (found && mPreloadPictureFoundSource.IsVoid()) {
      // Found an empty source, which counts
      mPreloadPictureFoundSource.SetIsVoid(false);
    }
  }
}

already_AddRefed<nsIURI> Document::ResolvePreloadImage(
    nsIURI* aBaseURI, const nsAString& aSrcAttr, const nsAString& aSrcsetAttr,
    const nsAString& aSizesAttr, bool* aIsImgSet) {
  nsString sourceURL;
  bool isImgSet;
  if (mPreloadPictureDepth == 1 && !mPreloadPictureFoundSource.IsVoid()) {
    // We're in a <picture> element and found a URI from a source previous to
    // this image, use it.
    sourceURL = mPreloadPictureFoundSource;
    isImgSet = true;
  } else {
    // Otherwise try to use this <img> as a source
    HTMLImageElement::SelectSourceForTagWithAttrs(
        this, false, aSrcAttr, aSrcsetAttr, aSizesAttr, VoidString(),
        VoidString(), sourceURL);
    isImgSet = !aSrcsetAttr.IsEmpty();
  }

  // Empty sources are not loaded by <img> (i.e. not resolved to the baseURI)
  if (sourceURL.IsEmpty()) {
    return nullptr;
  }

  // Construct into URI using passed baseURI (the parser may know of base URI
  // changes that have not reached us)
  nsresult rv;
  nsCOMPtr<nsIURI> uri;
  rv = nsContentUtils::NewURIWithDocumentCharset(getter_AddRefs(uri), sourceURL,
                                                 this, aBaseURI);
  if (NS_FAILED(rv)) {
    return nullptr;
  }

  *aIsImgSet = isImgSet;

  // We don't clear mPreloadPictureFoundSource because subsequent <img> tags in
  // this this <picture> share the same <sources> (though this is not valid per
  // spec)
  return uri.forget();
}

void Document::MaybePreLoadImage(
    nsIURI* uri, const nsAString& aCrossOriginAttr,
    enum mozilla::net::ReferrerPolicy aReferrerPolicy, bool aIsImgSet) {
  // Early exit if the img is already present in the img-cache
  // which indicates that the "real" load has already started and
  // that we shouldn't preload it.
  if (nsContentUtils::IsImageInCache(uri, this)) {
    return;
  }

  nsLoadFlags loadFlags = nsIRequest::LOAD_NORMAL |
                          nsContentUtils::CORSModeToLoadImageFlags(
                              Element::StringToCORSMode(aCrossOriginAttr));

  nsContentPolicyType policyType =
      aIsImgSet ? nsIContentPolicy::TYPE_IMAGESET
                : nsIContentPolicy::TYPE_INTERNAL_IMAGE_PRELOAD;

  // Image not in cache - trigger preload
  RefPtr<imgRequestProxy> request;
  nsresult rv = nsContentUtils::LoadImage(
      uri, static_cast<nsINode*>(this), this, NodePrincipal(), 0,
      GetDocumentURIAsReferrer(),  // uri of document used as referrer
      aReferrerPolicy,
      nullptr,  // no observer
      loadFlags, NS_LITERAL_STRING("img"), getter_AddRefs(request), policyType);

  // Pin image-reference to avoid evicting it from the img-cache before
  // the "real" load occurs. Unpinned in DispatchContentLoadedEvents and
  // unlink
  if (NS_SUCCEEDED(rv)) {
    mPreloadingImages.Put(uri, request.forget());
  }
}

void Document::MaybePreconnect(nsIURI* aOrigURI, mozilla::CORSMode aCORSMode) {
  NS_MutateURI mutator(aOrigURI);
  if (NS_FAILED(mutator.GetStatus())) {
    return;
  }

  // The URI created here is used in 2 contexts. One is nsISpeculativeConnect
  // which ignores the path and uses only the origin. The other is for the
  // document mPreloadedPreconnects de-duplication hash. Anonymous vs
  // non-Anonymous preconnects create different connections on the wire and
  // therefore should not be considred duplicates of each other and we
  // normalize the path before putting it in the hash to accomplish that.

  if (aCORSMode == CORS_ANONYMOUS) {
    mutator.SetPathQueryRef(NS_LITERAL_CSTRING("/anonymous"));
  } else {
    mutator.SetPathQueryRef(NS_LITERAL_CSTRING("/"));
  }

  nsCOMPtr<nsIURI> uri;
  nsresult rv = mutator.Finalize(uri);
  if (NS_FAILED(rv)) {
    return;
  }

  auto entry = mPreloadedPreconnects.LookupForAdd(uri);
  if (entry) {
    return;  // we found an existing entry
  }
  entry.OrInsert([]() { return true; });

  nsCOMPtr<nsISpeculativeConnect> speculator(
      do_QueryInterface(nsContentUtils::GetIOService()));
  if (!speculator) {
    return;
  }

  if (aCORSMode == CORS_ANONYMOUS) {
    speculator->SpeculativeAnonymousConnect(uri, NodePrincipal(), nullptr);
  } else {
    speculator->SpeculativeConnect(uri, NodePrincipal(), nullptr);
  }
}

void Document::ForgetImagePreload(nsIURI* aURI) {
  // Checking count is faster than hashing the URI in the common
  // case of empty table.
  if (mPreloadingImages.Count() != 0) {
    nsCOMPtr<imgIRequest> req;
    mPreloadingImages.Remove(aURI, getter_AddRefs(req));
    if (req) {
      // Make sure to cancel the request so imagelib knows it's gone.
      req->CancelAndForgetObserver(NS_BINDING_ABORTED);
    }
  }
}

void Document::UpdateDocumentStates(EventStates aMaybeChangedStates,
                                    bool aNotify) {
  EventStates oldStates = mDocumentState;
  if (aMaybeChangedStates.HasState(NS_DOCUMENT_STATE_RTL_LOCALE)) {
    if (IsDocumentRightToLeft()) {
      mDocumentState |= NS_DOCUMENT_STATE_RTL_LOCALE;
    } else {
      mDocumentState &= ~NS_DOCUMENT_STATE_RTL_LOCALE;
    }
  }

  if (aMaybeChangedStates.HasState(NS_DOCUMENT_STATE_WINDOW_INACTIVE)) {
    if (IsTopLevelWindowInactive()) {
      mDocumentState |= NS_DOCUMENT_STATE_WINDOW_INACTIVE;
    } else {
      mDocumentState &= ~NS_DOCUMENT_STATE_WINDOW_INACTIVE;
    }
  }

  EventStates changedStates = oldStates ^ mDocumentState;
  if (aNotify && !changedStates.IsEmpty()) {
    if (PresShell* ps = GetObservingPresShell()) {
      ps->DocumentStatesChanged(changedStates);
    }
  }
}

namespace {

/**
 * Stub for LoadSheet(), since all we want is to get the sheet into
 * the CSSLoader's style cache
 */
class StubCSSLoaderObserver final : public nsICSSLoaderObserver {
  ~StubCSSLoaderObserver() {}

 public:
  NS_IMETHOD
  StyleSheetLoaded(StyleSheet*, bool, nsresult) override { return NS_OK; }
  NS_DECL_ISUPPORTS
};
NS_IMPL_ISUPPORTS(StubCSSLoaderObserver, nsICSSLoaderObserver)

}  // namespace

void Document::PreloadStyle(
    nsIURI* uri, const Encoding* aEncoding, const nsAString& aCrossOriginAttr,
    const enum mozilla::net::ReferrerPolicy aReferrerPolicy,
    const nsAString& aIntegrity) {
  // The CSSLoader will retain this object after we return.
  nsCOMPtr<nsICSSLoaderObserver> obs = new StubCSSLoaderObserver();

  // Charset names are always ASCII.
  CSSLoader()->LoadSheet(uri, true, NodePrincipal(), aEncoding, obs,
                         Element::StringToCORSMode(aCrossOriginAttr),
                         aReferrerPolicy, aIntegrity);
}

RefPtr<StyleSheet> Document::LoadChromeSheetSync(nsIURI* uri) {
  RefPtr<StyleSheet> sheet;
  CSSLoader()->LoadSheetSync(uri, css::eAuthorSheetFeatures, false, &sheet);
  return sheet;
}

void Document::ResetDocumentDirection() {
  if (!(nsContentUtils::IsChromeDoc(this) || IsXULDocument())) {
    return;
  }
  UpdateDocumentStates(NS_DOCUMENT_STATE_RTL_LOCALE, true);
}

bool Document::IsDocumentRightToLeft() {
  if (!(nsContentUtils::IsChromeDoc(this) || IsXULDocument())) {
    return false;
  }
  // setting the localedir attribute on the root element forces a
  // specific direction for the document.
  Element* element = GetRootElement();
  if (element) {
    static Element::AttrValuesArray strings[] = {nsGkAtoms::ltr, nsGkAtoms::rtl,
                                                 nullptr};
    switch (element->FindAttrValueIn(kNameSpaceID_None, nsGkAtoms::localedir,
                                     strings, eCaseMatters)) {
      case 0:
        return false;
      case 1:
        return true;
      default:
        break;  // otherwise, not a valid value, so fall through
    }
  }

  // otherwise, get the locale from the chrome registry and
  // look up the intl.uidirection.<locale> preference
  nsCOMPtr<nsIXULChromeRegistry> reg =
      mozilla::services::GetXULChromeRegistryService();
  if (!reg) return false;

  nsAutoCString package;
  bool isChrome;
  if (NS_SUCCEEDED(mDocumentURI->SchemeIs("chrome", &isChrome)) && isChrome) {
    mDocumentURI->GetHostPort(package);
  } else {
    // use the 'global' package for about and resource uris.
    // otherwise, just default to left-to-right.
    bool isAbout, isResource;
    if (NS_SUCCEEDED(mDocumentURI->SchemeIs("about", &isAbout)) && isAbout) {
      package.AssignLiteral("global");
    } else if (NS_SUCCEEDED(mDocumentURI->SchemeIs("resource", &isResource)) &&
               isResource) {
      package.AssignLiteral("global");
    } else {
      return false;
    }
  }

  bool isRTL = false;
  reg->IsLocaleRTL(package, &isRTL);
  return isRTL;
}

class nsDelayedEventDispatcher : public Runnable {
 public:
  explicit nsDelayedEventDispatcher(nsTArray<nsCOMPtr<Document>>& aDocuments)
      : mozilla::Runnable("nsDelayedEventDispatcher") {
    mDocuments.SwapElements(aDocuments);
  }
  virtual ~nsDelayedEventDispatcher() {}

  NS_IMETHOD Run() override {
    FireOrClearDelayedEvents(mDocuments, true);
    return NS_OK;
  }

 private:
  nsTArray<nsCOMPtr<Document>> mDocuments;
};

static bool GetAndUnsuppressSubDocuments(Document* aDocument, void* aData) {
  if (aDocument->EventHandlingSuppressed() > 0) {
    aDocument->DecreaseEventSuppression();
    aDocument->ScriptLoader()->RemoveExecuteBlocker();
  }

  auto* docs = static_cast<nsTArray<nsCOMPtr<Document>>*>(aData);

  docs->AppendElement(aDocument);
  aDocument->EnumerateSubDocuments(GetAndUnsuppressSubDocuments, aData);
  return true;
}

void Document::UnsuppressEventHandlingAndFireEvents(bool aFireEvents) {
  nsTArray<nsCOMPtr<Document>> documents;
  GetAndUnsuppressSubDocuments(this, &documents);

  if (aFireEvents) {
    MOZ_RELEASE_ASSERT(NS_IsMainThread());
    nsCOMPtr<nsIRunnable> ded = new nsDelayedEventDispatcher(documents);
    Dispatch(TaskCategory::Other, ded.forget());
  } else {
    FireOrClearDelayedEvents(documents, false);
  }

  if (!EventHandlingSuppressed()) {
    MOZ_ASSERT(NS_IsMainThread());
    nsTArray<RefPtr<net::ChannelEventQueue>> queues;
    mSuspendedQueues.SwapElements(queues);
    for (net::ChannelEventQueue* queue : queues) {
      queue->Resume();
    }

    // If there have been any events driven by the refresh driver which were
    // delayed due to events being suppressed in this document, make sure there
    // is a refresh scheduled soon so the events will run.
    if (mHasDelayedRefreshEvent) {
      mHasDelayedRefreshEvent = false;

      if (mPresShell) {
        nsRefreshDriver* rd = mPresShell->GetPresContext()->RefreshDriver();
        rd->RunDelayedEventsSoon();
      }
    }
  }
}

void Document::AddSuspendedChannelEventQueue(net::ChannelEventQueue* aQueue) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(EventHandlingSuppressed());
  mSuspendedQueues.AppendElement(aQueue);
}

static bool SetSuppressedEventListenerInSubDocument(Document* aDocument,
                                                    void* aData) {
  aDocument->SetSuppressedEventListener(static_cast<EventListener*>(aData));
  return true;
}

void Document::SetSuppressedEventListener(EventListener* aListener) {
  mSuppressedEventListener = aListener;
  EnumerateSubDocuments(SetSuppressedEventListenerInSubDocument, aListener);
}

nsISupports* Document::GetCurrentContentSink() {
  return mParser ? mParser->GetContentSink() : nullptr;
}

Document* Document::GetTemplateContentsOwner() {
  if (!mTemplateContentsOwner) {
    bool hasHadScriptObject = true;
    nsIScriptGlobalObject* scriptObject =
        GetScriptHandlingObject(hasHadScriptObject);

    nsCOMPtr<Document> document;
    nsresult rv = NS_NewDOMDocument(getter_AddRefs(document),
                                    EmptyString(),  // aNamespaceURI
                                    EmptyString(),  // aQualifiedName
                                    nullptr,        // aDoctype
                                    Document::GetDocumentURI(),
                                    Document::GetDocBaseURI(), NodePrincipal(),
                                    true,          // aLoadedAsData
                                    scriptObject,  // aEventObject
                                    DocumentFlavorHTML);
    NS_ENSURE_SUCCESS(rv, nullptr);

    mTemplateContentsOwner = document;
    NS_ENSURE_TRUE(mTemplateContentsOwner, nullptr);

    if (!scriptObject) {
      mTemplateContentsOwner->SetScopeObject(GetScopeObject());
    }

    mTemplateContentsOwner->mHasHadScriptHandlingObject = hasHadScriptObject;

    // Set |mTemplateContentsOwner| as the template contents owner of itself so
    // that it is the template contents owner of nested template elements.
    mTemplateContentsOwner->mTemplateContentsOwner = mTemplateContentsOwner;
  }

  return mTemplateContentsOwner;
}

static already_AddRefed<nsPIDOMWindowOuter> FindTopWindowForElement(
    Element* element) {
  Document* document = element->OwnerDoc();
  if (!document) {
    return nullptr;
  }

  nsCOMPtr<nsPIDOMWindowOuter> window = document->GetWindow();
  if (!window) {
    return nullptr;
  }

  // Trying to find the top window (equivalent to window.top).
  if (nsCOMPtr<nsPIDOMWindowOuter> top = window->GetTop()) {
    window = top.forget();
  }
  return window.forget();
}

/**
 * nsAutoFocusEvent is used to dispatch a focus event for an
 * nsGenericHTMLFormElement with the autofocus attribute enabled.
 */
class nsAutoFocusEvent : public Runnable {
 public:
  explicit nsAutoFocusEvent(already_AddRefed<Element>&& aElement,
                            already_AddRefed<nsPIDOMWindowOuter>&& aTopWindow)
      : mozilla::Runnable("nsAutoFocusEvent"),
        mElement(aElement),
        mTopWindow(aTopWindow) {}

  NS_IMETHOD Run() override {
    nsCOMPtr<nsPIDOMWindowOuter> currentTopWindow =
        FindTopWindowForElement(mElement);
    if (currentTopWindow != mTopWindow) {
      // The element's top window changed from when the event was queued.
      // Don't take away focus from an unrelated window.
      return NS_OK;
    }

    // Don't steal focus from the user.
    if (mTopWindow->GetFocusedElement()) {
      return NS_OK;
    }

    FocusOptions options;
    ErrorResult rv;
    mElement->Focus(options, rv);
    return rv.StealNSResult();
  }

 private:
  nsCOMPtr<Element> mElement;
  nsCOMPtr<nsPIDOMWindowOuter> mTopWindow;
};

void Document::SetAutoFocusElement(Element* aAutoFocusElement) {
  if (mAutoFocusFired) {
    // Too late.
    return;
  }

  if (mAutoFocusElement) {
    // The spec disallows multiple autofocus elements, so we consider only the
    // first one to preserve the old behavior.
    return;
  }

  mAutoFocusElement = do_GetWeakReference(aAutoFocusElement);
  TriggerAutoFocus();
}

void Document::TriggerAutoFocus() {
  if (mAutoFocusFired) {
    return;
  }

  if (!mPresShell || !mPresShell->DidInitialize()) {
    // Delay autofocus until frames are constructed so that we don't thrash
    // style and layout calculations.
    return;
  }

  nsCOMPtr<Element> autoFocusElement = do_QueryReferent(mAutoFocusElement);
  if (autoFocusElement && autoFocusElement->OwnerDoc() == this) {
    mAutoFocusFired = true;

    nsCOMPtr<nsPIDOMWindowOuter> topWindow =
        FindTopWindowForElement(autoFocusElement);
    if (!topWindow) {
      return;
    }

    // NOTE: This may be removed in the future since the spec technically
    // allows autofocus after load.
    nsCOMPtr<Document> topDoc = topWindow->GetExtantDoc();
    if (topDoc &&
        topDoc->GetReadyStateEnum() == Document::READYSTATE_COMPLETE) {
      return;
    }

    nsCOMPtr<nsIRunnable> event =
        new nsAutoFocusEvent(autoFocusElement.forget(), topWindow.forget());
    nsresult rv = NS_DispatchToCurrentThread(event.forget());
    NS_ENSURE_SUCCESS_VOID(rv);
  }
}

void Document::SetScrollToRef(nsIURI* aDocumentURI) {
  if (!aDocumentURI) {
    return;
  }

  nsAutoCString ref;

  // Since all URI's that pass through here aren't URL's we can't
  // rely on the nsIURI implementation for providing a way for
  // finding the 'ref' part of the URI, we'll haveto revert to
  // string routines for finding the data past '#'

  nsresult rv = aDocumentURI->GetSpec(ref);
  if (NS_FAILED(rv)) {
    Unused << aDocumentURI->GetRef(mScrollToRef);
    return;
  }

  nsReadingIterator<char> start, end;

  ref.BeginReading(start);
  ref.EndReading(end);

  if (FindCharInReadable('#', start, end)) {
    ++start;  // Skip over the '#'

    mScrollToRef = Substring(start, end);
  }
}

void Document::ScrollToRef() {
  if (mScrolledToRefAlready) {
    RefPtr<PresShell> presShell = GetPresShell();
    if (presShell) {
      presShell->ScrollToAnchor();
    }
    return;
  }

  if (mScrollToRef.IsEmpty()) {
    return;
  }

  RefPtr<PresShell> presShell = GetPresShell();
  if (presShell) {
    nsresult rv = NS_ERROR_FAILURE;
    // We assume that the bytes are in UTF-8, as it says in the spec:
    // http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.1
    NS_ConvertUTF8toUTF16 ref(mScrollToRef);
    // Check an empty string which might be caused by the UTF-8 conversion
    if (!ref.IsEmpty()) {
      // Note that GoToAnchor will handle flushing layout as needed.
      rv = presShell->GoToAnchor(ref, mChangeScrollPosWhenScrollingToRef);
    } else {
      rv = NS_ERROR_FAILURE;
    }

    if (NS_FAILED(rv)) {
      nsAutoCString buff;
      const bool unescaped =
          NS_UnescapeURL(mScrollToRef.BeginReading(), mScrollToRef.Length(),
                         /*aFlags =*/0, buff);

      // This attempt is only necessary if characters were unescaped.
      if (unescaped) {
        NS_ConvertUTF8toUTF16 utf16Str(buff);
        if (!utf16Str.IsEmpty()) {
          rv = presShell->GoToAnchor(utf16Str,
                                     mChangeScrollPosWhenScrollingToRef);
        }
      }

      // If UTF-8 URI failed then try to assume the string as a
      // document's charset.
      if (NS_FAILED(rv)) {
        const Encoding* encoding = GetDocumentCharacterSet();
        rv = encoding->DecodeWithoutBOMHandling(unescaped ? buff : mScrollToRef,
                                                ref);
        if (NS_SUCCEEDED(rv) && !ref.IsEmpty()) {
          rv = presShell->GoToAnchor(ref, mChangeScrollPosWhenScrollingToRef);
        }
      }
    }
    if (NS_SUCCEEDED(rv)) {
      mScrolledToRefAlready = true;
    }
  }
}

void Document::RegisterActivityObserver(nsISupports* aSupports) {
  if (!mActivityObservers) {
    mActivityObservers = new nsTHashtable<nsPtrHashKey<nsISupports>>();
  }
  mActivityObservers->PutEntry(aSupports);
}

bool Document::UnregisterActivityObserver(nsISupports* aSupports) {
  if (!mActivityObservers) {
    return false;
  }
  nsPtrHashKey<nsISupports>* entry = mActivityObservers->GetEntry(aSupports);
  if (!entry) {
    return false;
  }
  mActivityObservers->RemoveEntry(entry);
  return true;
}

void Document::EnumerateActivityObservers(
    ActivityObserverEnumerator aEnumerator, void* aData) {
  if (!mActivityObservers) return;

  for (auto iter = mActivityObservers->ConstIter(); !iter.Done(); iter.Next()) {
    aEnumerator(iter.Get()->GetKey(), aData);
  }
}

void Document::RegisterPendingLinkUpdate(Link* aLink) {
  if (aLink->HasPendingLinkUpdate()) {
    return;
  }

  aLink->SetHasPendingLinkUpdate();

  if (!mHasLinksToUpdateRunnable && !mFlushingPendingLinkUpdates) {
    nsCOMPtr<nsIRunnable> event =
        NewRunnableMethod("Document::FlushPendingLinkUpdatesFromRunnable", this,
                          &Document::FlushPendingLinkUpdatesFromRunnable);
    // Do this work in a second in the worst case.
    nsresult rv = NS_DispatchToCurrentThreadQueue(event.forget(), 1000,
                                                  EventQueuePriority::Idle);
    if (NS_FAILED(rv)) {
      // If during shutdown posting a runnable doesn't succeed, we probably
      // don't need to update link states.
      return;
    }
    mHasLinksToUpdateRunnable = true;
  }

  mLinksToUpdate.InfallibleAppend(aLink);
}

void Document::FlushPendingLinkUpdatesFromRunnable() {
  MOZ_ASSERT(mHasLinksToUpdateRunnable);
  mHasLinksToUpdateRunnable = false;
  FlushPendingLinkUpdates();
}

void Document::FlushPendingLinkUpdates() {
  if (mFlushingPendingLinkUpdates) {
    return;
  }

  auto restore = MakeScopeExit([&] { mFlushingPendingLinkUpdates = false; });
  mFlushingPendingLinkUpdates = true;

  while (!mLinksToUpdate.IsEmpty()) {
    LinksToUpdateList links(std::move(mLinksToUpdate));
    for (auto iter = links.Iter(); !iter.Done(); iter.Next()) {
      Link* link = iter.Get();
      Element* element = link->GetElement();
      if (element->OwnerDoc() == this) {
        link->ClearHasPendingLinkUpdate();
        if (element->IsInComposedDoc()) {
          element->UpdateLinkState(link->LinkState());
        }
      }
    }
  }
}

already_AddRefed<Document> Document::CreateStaticClone(
    nsIDocShell* aCloneContainer) {
  mCreatingStaticClone = true;

  // Make document use different container during cloning.
  RefPtr<nsDocShell> originalShell = mDocumentContainer.get();
  SetContainer(static_cast<nsDocShell*>(aCloneContainer));
  ErrorResult rv;
  nsCOMPtr<nsINode> clonedNode = this->CloneNode(true, rv);
  SetContainer(originalShell);

  nsCOMPtr<Document> clonedDoc;
  if (rv.Failed()) {
    // Don't return yet; we need to reset mCreatingStaticClone
    rv.SuppressException();
  } else {
    clonedDoc = do_QueryInterface(clonedNode);
    if (clonedDoc) {
      if (IsStaticDocument()) {
        clonedDoc->mOriginalDocument = mOriginalDocument;
        mOriginalDocument->mLatestStaticClone = clonedDoc;
      } else {
        clonedDoc->mOriginalDocument = this;
        mLatestStaticClone = clonedDoc;
      }

      clonedDoc->mOriginalDocument->mStaticCloneCount++;

      size_t sheetsCount = SheetCount();
      for (size_t i = 0; i < sheetsCount; ++i) {
        RefPtr<StyleSheet> sheet = SheetAt(i);
        if (sheet) {
          if (sheet->IsApplicable()) {
            RefPtr<StyleSheet> clonedSheet =
                sheet->Clone(nullptr, nullptr, clonedDoc, nullptr);
            NS_WARNING_ASSERTION(clonedSheet,
                                 "Cloning a stylesheet didn't work!");
            if (clonedSheet) {
              clonedDoc->AddStyleSheet(clonedSheet);
            }
          }
        }
      }

      for (int t = 0; t < AdditionalSheetTypeCount; ++t) {
        auto& sheets = mAdditionalSheets[additionalSheetType(t)];
        for (StyleSheet* sheet : sheets) {
          if (sheet->IsApplicable()) {
            RefPtr<StyleSheet> clonedSheet =
                sheet->Clone(nullptr, nullptr, clonedDoc, nullptr);
            NS_WARNING_ASSERTION(clonedSheet,
                                 "Cloning a stylesheet didn't work!");
            if (clonedSheet) {
              clonedDoc->AddAdditionalStyleSheet(additionalSheetType(t),
                                                 clonedSheet);
            }
          }
        }
      }

      // Font faces created with the JS API will not be reflected in the
      // stylesheets and need to be copied over to the cloned document.
      if (const FontFaceSet* set = GetFonts()) {
        set->CopyNonRuleFacesTo(clonedDoc->Fonts());
      }
    }
  }
  mCreatingStaticClone = false;
  return clonedDoc.forget();
}

void Document::UnlinkOriginalDocumentIfStatic() {
  if (IsStaticDocument() && mOriginalDocument) {
    MOZ_ASSERT(mOriginalDocument->mStaticCloneCount > 0);
    mOriginalDocument->mStaticCloneCount--;
    mOriginalDocument = nullptr;
  }
  MOZ_ASSERT(!mOriginalDocument);
}

nsresult Document::ScheduleFrameRequestCallback(FrameRequestCallback& aCallback,
                                                int32_t* aHandle) {
  if (mFrameRequestCallbackCounter == INT32_MAX) {
    // Can't increment without overflowing; bail out
    return NS_ERROR_NOT_AVAILABLE;
  }
  int32_t newHandle = ++mFrameRequestCallbackCounter;

  DebugOnly<FrameRequest*> request =
      mFrameRequestCallbacks.AppendElement(FrameRequest(aCallback, newHandle));
  NS_ASSERTION(request, "This is supposed to be infallible!");
  UpdateFrameRequestCallbackSchedulingState();

  *aHandle = newHandle;
  return NS_OK;
}

void Document::CancelFrameRequestCallback(int32_t aHandle) {
  // mFrameRequestCallbacks is stored sorted by handle
  if (mFrameRequestCallbacks.RemoveElementSorted(aHandle)) {
    UpdateFrameRequestCallbackSchedulingState();
  } else {
    Unused << mCanceledFrameRequestCallbacks.put(aHandle);
  }
}

bool Document::IsCanceledFrameRequestCallback(int32_t aHandle) const {
  return !mCanceledFrameRequestCallbacks.empty() &&
         mCanceledFrameRequestCallbacks.has(aHandle);
}

nsresult Document::GetStateObject(nsIVariant** aState) {
  // Get the document's current state object. This is the object backing both
  // history.state and popStateEvent.state.
  //
  // mStateObjectContainer may be null; this just means that there's no
  // current state object.

  if (!mStateObjectCached && mStateObjectContainer) {
    AutoJSAPI jsapi;
    // Init with null is "OK" in the sense that it will just fail.
    if (!jsapi.Init(GetScopeObject())) {
      return NS_ERROR_UNEXPECTED;
    }
    mStateObjectContainer->DeserializeToVariant(
        jsapi.cx(), getter_AddRefs(mStateObjectCached));
  }

  NS_IF_ADDREF(*aState = mStateObjectCached);
  return NS_OK;
}

void Document::SetNavigationTiming(nsDOMNavigationTiming* aTiming) {
  mTiming = aTiming;
  if (!mLoadingTimeStamp.IsNull() && mTiming) {
    mTiming->SetDOMLoadingTimeStamp(GetDocumentURI(), mLoadingTimeStamp);
  }
}

nsContentList* Document::ImageMapList() {
  if (!mImageMaps) {
    mImageMaps = new nsContentList(this, kNameSpaceID_XHTML, nsGkAtoms::map,
                                   nsGkAtoms::map);
  }

  return mImageMaps;
}

#define DEPRECATED_OPERATION(_op) #_op "Warning",
static const char* kDeprecationWarnings[] = {
#include "nsDeprecatedOperationList.h"
    nullptr};
#undef DEPRECATED_OPERATION

#define DOCUMENT_WARNING(_op) #_op "Warning",
static const char* kDocumentWarnings[] = {
#include "nsDocumentWarningList.h"
    nullptr};
#undef DOCUMENT_WARNING

static UseCounter OperationToUseCounter(
    Document::DeprecatedOperations aOperation) {
  switch (aOperation) {
#define DEPRECATED_OPERATION(_op) \
  case Document::e##_op:          \
    return eUseCounter_##_op;
#include "nsDeprecatedOperationList.h"
#undef DEPRECATED_OPERATION
    default:
      MOZ_CRASH();
  }
}

bool Document::HasWarnedAbout(DeprecatedOperations aOperation) const {
  return mDeprecationWarnedAbout[aOperation];
}

void Document::WarnOnceAbout(DeprecatedOperations aOperation,
                             bool asError /* = false */) const {
  MOZ_ASSERT(NS_IsMainThread());
  if (HasWarnedAbout(aOperation)) {
    return;
  }
  mDeprecationWarnedAbout[aOperation] = true;
  // Don't count deprecated operations for about pages since those pages
  // are almost in our control, and we always need to remove uses there
  // before we remove the operation itself anyway.
  if (!IsAboutPage()) {
    const_cast<Document*>(this)->SetDocumentAndPageUseCounter(
        OperationToUseCounter(aOperation));
  }
  uint32_t flags =
      asError ? nsIScriptError::errorFlag : nsIScriptError::warningFlag;
  nsContentUtils::ReportToConsole(flags, NS_LITERAL_CSTRING("DOM Core"), this,
                                  nsContentUtils::eDOM_PROPERTIES,
                                  kDeprecationWarnings[aOperation]);
}

bool Document::HasWarnedAbout(DocumentWarnings aWarning) const {
  return mDocWarningWarnedAbout[aWarning];
}

void Document::WarnOnceAbout(DocumentWarnings aWarning,
                             bool asError /* = false */,
                             const char16_t** aParams /* = nullptr */,
                             uint32_t aParamsLength /* = 0 */) const {
  MOZ_ASSERT(NS_IsMainThread());
  if (HasWarnedAbout(aWarning)) {
    return;
  }
  mDocWarningWarnedAbout[aWarning] = true;
  uint32_t flags =
      asError ? nsIScriptError::errorFlag : nsIScriptError::warningFlag;
  nsContentUtils::ReportToConsole(flags, NS_LITERAL_CSTRING("DOM Core"), this,
                                  nsContentUtils::eDOM_PROPERTIES,
                                  kDocumentWarnings[aWarning], aParams,
                                  aParamsLength);
}

mozilla::dom::ImageTracker* Document::ImageTracker() {
  if (!mImageTracker) {
    mImageTracker = new mozilla::dom::ImageTracker;
  }
  return mImageTracker;
}

static bool AllSubDocumentPluginEnum(Document* aDocument, void* userArg) {
  nsTArray<nsIObjectLoadingContent*>* plugins =
      reinterpret_cast<nsTArray<nsIObjectLoadingContent*>*>(userArg);
  MOZ_ASSERT(plugins);
  aDocument->GetPlugins(*plugins);
  return true;
}

void Document::GetPlugins(nsTArray<nsIObjectLoadingContent*>& aPlugins) {
  aPlugins.SetCapacity(aPlugins.Length() + mPlugins.Count());
  for (auto iter = mPlugins.ConstIter(); !iter.Done(); iter.Next()) {
    aPlugins.AppendElement(iter.Get()->GetKey());
  }
  EnumerateSubDocuments(AllSubDocumentPluginEnum, &aPlugins);
}

void Document::ScheduleSVGUseElementShadowTreeUpdate(
    SVGUseElement& aUseElement) {
  MOZ_ASSERT(aUseElement.IsInComposedDoc());

  mSVGUseElementsNeedingShadowTreeUpdate.PutEntry(&aUseElement);

  if (PresShell* presShell = GetPresShell()) {
    presShell->EnsureStyleFlush();
  }
}

void Document::DoUpdateSVGUseElementShadowTrees() {
  MOZ_ASSERT(!mSVGUseElementsNeedingShadowTreeUpdate.IsEmpty());
  nsTArray<RefPtr<SVGUseElement>> useElementsToUpdate;

  do {
    useElementsToUpdate.Clear();
    useElementsToUpdate.SetCapacity(
        mSVGUseElementsNeedingShadowTreeUpdate.Count());

    {
      for (auto iter = mSVGUseElementsNeedingShadowTreeUpdate.ConstIter();
           !iter.Done(); iter.Next()) {
        useElementsToUpdate.AppendElement(iter.Get()->GetKey());
      }
      mSVGUseElementsNeedingShadowTreeUpdate.Clear();
    }

    for (auto& useElement : useElementsToUpdate) {
      if (MOZ_UNLIKELY(!useElement->IsInComposedDoc())) {
        // The element was in another <use> shadow tree which we processed
        // already and also needed an update, and is removed from the document
        // now, so nothing to do here.
        MOZ_ASSERT(useElementsToUpdate.Length() > 1);
        continue;
      }
      useElement->UpdateShadowTree();
    }
  } while (!mSVGUseElementsNeedingShadowTreeUpdate.IsEmpty());
}

void Document::NotifyMediaFeatureValuesChanged() {
  for (auto iter = mResponsiveContent.ConstIter(); !iter.Done(); iter.Next()) {
    RefPtr<HTMLImageElement> imageElement = iter.Get()->GetKey();
    imageElement->MediaFeatureValuesChanged();
  }
}

already_AddRefed<Touch> Document::CreateTouch(
    nsGlobalWindowInner* aView, EventTarget* aTarget, int32_t aIdentifier,
    int32_t aPageX, int32_t aPageY, int32_t aScreenX, int32_t aScreenY,
    int32_t aClientX, int32_t aClientY, int32_t aRadiusX, int32_t aRadiusY,
    float aRotationAngle, float aForce) {
  RefPtr<Touch> touch =
      new Touch(aTarget, aIdentifier, aPageX, aPageY, aScreenX, aScreenY,
                aClientX, aClientY, aRadiusX, aRadiusY, aRotationAngle, aForce);
  return touch.forget();
}

already_AddRefed<TouchList> Document::CreateTouchList() {
  RefPtr<TouchList> retval = new TouchList(ToSupports(this));
  return retval.forget();
}

already_AddRefed<TouchList> Document::CreateTouchList(
    Touch& aTouch, const Sequence<OwningNonNull<Touch>>& aTouches) {
  RefPtr<TouchList> retval = new TouchList(ToSupports(this));
  retval->Append(&aTouch);
  for (uint32_t i = 0; i < aTouches.Length(); ++i) {
    retval->Append(aTouches[i].get());
  }
  return retval.forget();
}

already_AddRefed<TouchList> Document::CreateTouchList(
    const Sequence<OwningNonNull<Touch>>& aTouches) {
  RefPtr<TouchList> retval = new TouchList(ToSupports(this));
  for (uint32_t i = 0; i < aTouches.Length(); ++i) {
    retval->Append(aTouches[i].get());
  }
  return retval.forget();
}

already_AddRefed<nsDOMCaretPosition> Document::CaretPositionFromPoint(
    float aX, float aY) {
  using FrameForPointOption = nsLayoutUtils::FrameForPointOption;

  nscoord x = nsPresContext::CSSPixelsToAppUnits(aX);
  nscoord y = nsPresContext::CSSPixelsToAppUnits(aY);
  nsPoint pt(x, y);

  FlushPendingNotifications(FlushType::Layout);

  PresShell* presShell = GetPresShell();
  if (!presShell) {
    return nullptr;
  }

  nsIFrame* rootFrame = presShell->GetRootFrame();

  // XUL docs, unlike HTML, have no frame tree until everything's done loading
  if (!rootFrame) {
    return nullptr;
  }

  nsIFrame* ptFrame = nsLayoutUtils::GetFrameForPoint(
      rootFrame, pt,
      {FrameForPointOption::IgnorePaintSuppression,
       FrameForPointOption::IgnoreCrossDoc});
  if (!ptFrame) {
    return nullptr;
  }

  // We require frame-relative coordinates for GetContentOffsetsFromPoint.
  nsPoint aOffset;
  nsCOMPtr<nsIWidget> widget = nsContentUtils::GetWidget(presShell, &aOffset);
  LayoutDeviceIntPoint refPoint = nsContentUtils::ToWidgetPoint(
      CSSPoint(aX, aY), aOffset, GetPresContext());
  nsPoint adjustedPoint =
      nsLayoutUtils::GetEventCoordinatesRelativeTo(widget, refPoint, ptFrame);

  nsFrame::ContentOffsets offsets =
      ptFrame->GetContentOffsetsFromPoint(adjustedPoint);

  nsCOMPtr<nsIContent> node = offsets.content;
  uint32_t offset = offsets.offset;
  nsCOMPtr<nsIContent> anonNode = node;
  bool nodeIsAnonymous = node && node->IsInNativeAnonymousSubtree();
  if (nodeIsAnonymous) {
    node = ptFrame->GetContent();
    nsIContent* nonanon = node->FindFirstNonChromeOnlyAccessContent();
    HTMLTextAreaElement* textArea = HTMLTextAreaElement::FromNode(nonanon);
    nsITextControlFrame* textFrame = do_QueryFrame(nonanon->GetPrimaryFrame());
    nsNumberControlFrame* numberFrame =
        do_QueryFrame(nonanon->GetPrimaryFrame());
    if (textFrame || numberFrame) {
      // If the anonymous content node has a child, then we need to make sure
      // that we get the appropriate child, as otherwise the offset may not be
      // correct when we construct a range for it.
      nsCOMPtr<nsIContent> firstChild = anonNode->GetFirstChild();
      if (firstChild) {
        anonNode = firstChild;
      }

      if (textArea) {
        offset =
            nsContentUtils::GetAdjustedOffsetInTextControl(ptFrame, offset);
      }

      node = nonanon;
    } else {
      node = nullptr;
      offset = 0;
    }
  }

  RefPtr<nsDOMCaretPosition> aCaretPos = new nsDOMCaretPosition(node, offset);
  if (nodeIsAnonymous) {
    aCaretPos->SetAnonymousContentNode(anonNode);
  }
  return aCaretPos.forget();
}

bool Document::IsPotentiallyScrollable(HTMLBodyElement* aBody) {
  // We rely on correct frame information here, so need to flush frames.
  FlushPendingNotifications(FlushType::Frames);

  // An element is potentially scrollable if all of the following conditions are
  // true:

  // The element has an associated CSS layout box.
  nsIFrame* bodyFrame = aBody->GetPrimaryFrame();
  if (!bodyFrame) {
    return false;
  }

  // The element is not the HTML body element, or it is and the root element's
  // used value of the overflow-x or overflow-y properties is not visible.
  MOZ_ASSERT(aBody->GetParent() == aBody->OwnerDoc()->GetRootElement());
  nsIFrame* parentFrame = aBody->GetParent()->GetPrimaryFrame();
  if (parentFrame &&
      parentFrame->StyleDisplay()->mOverflowX == StyleOverflow::Visible &&
      parentFrame->StyleDisplay()->mOverflowY == StyleOverflow::Visible) {
    return false;
  }

  // The element's used value of the overflow-x or overflow-y properties is not
  // visible.
  if (bodyFrame->StyleDisplay()->mOverflowX == StyleOverflow::Visible &&
      bodyFrame->StyleDisplay()->mOverflowY == StyleOverflow::Visible) {
    return false;
  }

  return true;
}

Element* Document::GetScrollingElement() {
  // Keep this in sync with IsScrollingElement.
  if (GetCompatibilityMode() == eCompatibility_NavQuirks) {
    RefPtr<HTMLBodyElement> body = GetBodyElement();
    if (body && !IsPotentiallyScrollable(body)) {
      return body;
    }

    return nullptr;
  }

  return GetRootElement();
}

bool Document::IsScrollingElement(Element* aElement) {
  // Keep this in sync with GetScrollingElement.
  MOZ_ASSERT(aElement);

  if (GetCompatibilityMode() != eCompatibility_NavQuirks) {
    return aElement == GetRootElement();
  }

  // In the common case when aElement != body, avoid refcounting.
  HTMLBodyElement* body = GetBodyElement();
  if (aElement != body) {
    return false;
  }

  // Now we know body is non-null, since aElement is not null.  It's the
  // scrolling element for the document if it itself is not potentially
  // scrollable.
  RefPtr<HTMLBodyElement> strongBody(body);
  return !IsPotentiallyScrollable(strongBody);
}

class UnblockParsingPromiseHandler final : public PromiseNativeHandler {
 public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_CLASS(UnblockParsingPromiseHandler)

  explicit UnblockParsingPromiseHandler(Document* aDocument, Promise* aPromise,
                                        const BlockParsingOptions& aOptions)
      : mPromise(aPromise) {
    nsCOMPtr<nsIParser> parser = aDocument->CreatorParserOrNull();
    if (parser &&
        (aOptions.mBlockScriptCreated || !parser->IsScriptCreated())) {
      parser->BlockParser();
      mParser = do_GetWeakReference(parser);
      mDocument = aDocument;
      mDocument->BlockOnload();
      mDocument->BlockDOMContentLoaded();
    }
  }

  void ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override {
    MaybeUnblockParser();

    mPromise->MaybeResolve(aCx, aValue);
  }

  void RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override {
    MaybeUnblockParser();

    mPromise->MaybeReject(aCx, aValue);
  }

 protected:
  virtual ~UnblockParsingPromiseHandler() {
    // If we're being cleaned up by the cycle collector, our mDocument reference
    // may have been unlinked while our mParser weak reference is still alive.
    if (mDocument) {
      MaybeUnblockParser();
    }
  }

 private:
  void MaybeUnblockParser() {
    nsCOMPtr<nsIParser> parser = do_QueryReferent(mParser);
    if (parser) {
      MOZ_DIAGNOSTIC_ASSERT(mDocument);
      nsCOMPtr<nsIParser> docParser = mDocument->CreatorParserOrNull();
      if (parser == docParser) {
        parser->UnblockParser();
        parser->ContinueInterruptedParsingAsync();
      }
    }
    if (mDocument) {
      // We blocked DOMContentLoaded and load events on this document.  Unblock
      // them.  Note that we want to do that no matter what's going on with the
      // parser state for this document.  Maybe someone caused it to stop being
      // parsed, so CreatorParserOrNull() is returning null, but we still want
      // to unblock these.
      mDocument->UnblockDOMContentLoaded();
      mDocument->UnblockOnload(false);
    }
    mParser = nullptr;
    mDocument = nullptr;
  }

  nsWeakPtr mParser;
  RefPtr<Promise> mPromise;
  RefPtr<Document> mDocument;
};

NS_IMPL_CYCLE_COLLECTION(UnblockParsingPromiseHandler, mDocument, mPromise)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(UnblockParsingPromiseHandler)
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(UnblockParsingPromiseHandler)
NS_IMPL_CYCLE_COLLECTING_RELEASE(UnblockParsingPromiseHandler)

already_AddRefed<Promise> Document::BlockParsing(
    Promise& aPromise, const BlockParsingOptions& aOptions, ErrorResult& aRv) {
  RefPtr<Promise> resultPromise =
      Promise::Create(aPromise.GetParentObject(), aRv);
  if (aRv.Failed()) {
    return nullptr;
  }

  RefPtr<PromiseNativeHandler> promiseHandler =
      new UnblockParsingPromiseHandler(this, resultPromise, aOptions);
  aPromise.AppendNativeHandler(promiseHandler);

  return resultPromise.forget();
}

already_AddRefed<nsIURI> Document::GetMozDocumentURIIfNotForErrorPages() {
  if (mFailedChannel) {
    nsCOMPtr<nsIURI> failedURI;
    if (NS_SUCCEEDED(mFailedChannel->GetURI(getter_AddRefs(failedURI)))) {
      return failedURI.forget();
    }
  }

  nsCOMPtr<nsIURI> uri = GetDocumentURIObject();
  if (!uri) {
    return nullptr;
  }

  return uri.forget();
}

Promise* Document::GetDocumentReadyForIdle(ErrorResult& aRv) {
  if (!mReadyForIdle) {
    nsIGlobalObject* global = GetScopeObject();
    if (!global) {
      aRv.Throw(NS_ERROR_NOT_AVAILABLE);
      return nullptr;
    }

    mReadyForIdle = Promise::Create(global, aRv);
    if (aRv.Failed()) {
      return nullptr;
    }
  }

  return mReadyForIdle;
}

void Document::MaybeResolveReadyForIdle() {
  IgnoredErrorResult rv;
  Promise* readyPromise = GetDocumentReadyForIdle(rv);
  if (readyPromise) {
    readyPromise->MaybeResolve(this);
  }
}

FeaturePolicy* Document::Policy() const {
  // The policy is created when the document is initialized. We _must_ have a
  // policy here even if the featurePolicy pref is off. If this assertion fails,
  // it means that ::Policy() is called before ::StartDocumentLoad().
  MOZ_ASSERT(mFeaturePolicy);
  return mFeaturePolicy;
}

nsIDOMXULCommandDispatcher* Document::GetCommandDispatcher() {
  // Only chrome documents are allowed to use command dispatcher.
  if (!nsContentUtils::IsChromeDoc(this)) {
    return nullptr;
  }
  if (!mCommandDispatcher) {
    // Create our command dispatcher and hook it up.
    mCommandDispatcher = new nsXULCommandDispatcher(this);
  }
  return mCommandDispatcher;
}

void Document::InitializeXULBroadcastManager() {
  if (mXULBroadcastManager) {
    return;
  }
  mXULBroadcastManager = new XULBroadcastManager(this);
}

static bool NodeHasScopeObject(nsINode* node) {
  MOZ_ASSERT(node, "Must not be called with null.");

  // Window root occasionally keeps alive a node of a document whose
  // window is already dead. If in this brief period someone calls
  // GetPopupNode and we return that node, we can end up creating a
  // reflector for the node in the wrong global (the current global,
  // not the document global, because we won't know what the document
  // global is).  Returning an orphan node like that to JS would be a
  // bug anyway, so to avoid this, let's do the same check as fetching
  // GetParentObject() on the document does to determine the scope and
  // if there is no usable scope object let's report that and return
  // null from Document::GetPopupNode instead of returning a node that
  // will get a reflector in the wrong scope.
  Document* doc = node->OwnerDoc();
  MOZ_ASSERT(doc, "This should never happen.");

  nsIGlobalObject* global = doc->GetScopeObject();
  return global ? global->HasJSGlobal() : false;
}

already_AddRefed<nsPIWindowRoot> Document::GetWindowRoot() {
  if (!mDocumentContainer) {
    return nullptr;
  }
  // XXX It's unclear why this can't just use GetWindow().
  nsCOMPtr<nsPIDOMWindowOuter> piWin = mDocumentContainer->GetWindow();
  return piWin ? piWin->GetTopWindowRoot() : nullptr;
}

already_AddRefed<nsINode> Document::GetPopupNode() {
  nsCOMPtr<nsINode> node;
  nsCOMPtr<nsPIWindowRoot> rootWin = GetWindowRoot();
  if (rootWin) {
    node = rootWin->GetPopupNode();  // addref happens here
  }

  if (!node) {
    nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
    if (pm) {
      node = pm->GetLastTriggerPopupNode(this);
    }
  }

  if (node && NodeHasScopeObject(node)) {
    return node.forget();
  }

  return nullptr;
}

void Document::SetPopupNode(nsINode* aNode) {
  nsCOMPtr<nsPIWindowRoot> rootWin = GetWindowRoot();
  if (rootWin) {
    rootWin->SetPopupNode(aNode);
  }
}

// Returns the rangeOffset element from the XUL Popup Manager. This is for
// chrome callers only.
nsINode* Document::GetPopupRangeParent(ErrorResult& aRv) {
  nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
  if (!pm) {
    aRv.Throw(NS_ERROR_FAILURE);
    return nullptr;
  }

  return pm->GetMouseLocationParent();
}

// Returns the rangeOffset element from the XUL Popup Manager.
int32_t Document::GetPopupRangeOffset(ErrorResult& aRv) {
  nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
  if (!pm) {
    aRv.Throw(NS_ERROR_FAILURE);
    return 0;
  }

  return pm->MouseLocationOffset();
}

already_AddRefed<nsINode> Document::GetTooltipNode() {
  nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
  if (pm) {
    nsCOMPtr<nsINode> node = pm->GetLastTriggerTooltipNode(this);
    if (node) {
      return node.forget();
    }
  }

  return nullptr;
}

nsIHTMLCollection* Document::Children() {
  if (!mChildrenCollection) {
    mChildrenCollection =
        new nsContentList(this, kNameSpaceID_Wildcard, nsGkAtoms::_asterisk,
                          nsGkAtoms::_asterisk, false);
  }

  return mChildrenCollection;
}

uint32_t Document::ChildElementCount() { return Children()->Length(); }

// Singleton class to manage the list of fullscreen documents which are the
// root of a branch which contains fullscreen documents. We maintain this list
// so that we can easily exit all windows from fullscreen when the user
// presses the escape key.
class FullscreenRoots {
 public:
  // Adds the root of given document to the manager. Calling this method
  // with a document whose root is already contained has no effect.
  static void Add(Document* aDoc);

  // Iterates over every root in the root list, and calls aFunction, passing
  // each root once to aFunction. It is safe to call Add() and Remove() while
  // iterating over the list (i.e. in aFunction). Documents that are removed
  // from the manager during traversal are not traversed, and documents that
  // are added to the manager during traversal are also not traversed.
  static void ForEach(void (*aFunction)(Document* aDoc));

  // Removes the root of a specific document from the manager.
  static void Remove(Document* aDoc);

  // Returns true if all roots added to the list have been removed.
  static bool IsEmpty();

 private:
  FullscreenRoots() { MOZ_COUNT_CTOR(FullscreenRoots); }
  ~FullscreenRoots() { MOZ_COUNT_DTOR(FullscreenRoots); }

  enum { NotFound = uint32_t(-1) };
  // Looks in mRoots for aRoot. Returns the index if found, otherwise NotFound.
  static uint32_t Find(Document* aRoot);

  // Returns true if aRoot is in the list of fullscreen roots.
  static bool Contains(Document* aRoot);

  // Singleton instance of the FullscreenRoots. This is instantiated when a
  // root is added, and it is deleted when the last root is removed.
  static FullscreenRoots* sInstance;

  // List of weak pointers to roots.
  nsTArray<nsWeakPtr> mRoots;
};

FullscreenRoots* FullscreenRoots::sInstance = nullptr;

/* static */
void FullscreenRoots::ForEach(void (*aFunction)(Document* aDoc)) {
  if (!sInstance) {
    return;
  }
  // Create a copy of the roots array, and iterate over the copy. This is so
  // that if an element is removed from mRoots we don't mess up our iteration.
  nsTArray<nsWeakPtr> roots(sInstance->mRoots);
  // Call aFunction on all entries.
  for (uint32_t i = 0; i < roots.Length(); i++) {
    nsCOMPtr<Document> root = do_QueryReferent(roots[i]);
    // Check that the root isn't in the manager. This is so that new additions
    // while we were running don't get traversed.
    if (root && FullscreenRoots::Contains(root)) {
      aFunction(root);
    }
  }
}

/* static */
bool FullscreenRoots::Contains(Document* aRoot) {
  return FullscreenRoots::Find(aRoot) != NotFound;
}

/* static */
void FullscreenRoots::Add(Document* aDoc) {
  nsCOMPtr<Document> root = nsContentUtils::GetRootDocument(aDoc);
  if (!FullscreenRoots::Contains(root)) {
    if (!sInstance) {
      sInstance = new FullscreenRoots();
    }
    sInstance->mRoots.AppendElement(do_GetWeakReference(root));
  }
}

/* static */
uint32_t FullscreenRoots::Find(Document* aRoot) {
  if (!sInstance) {
    return NotFound;
  }
  nsTArray<nsWeakPtr>& roots = sInstance->mRoots;
  for (uint32_t i = 0; i < roots.Length(); i++) {
    nsCOMPtr<Document> otherRoot(do_QueryReferent(roots[i]));
    if (otherRoot == aRoot) {
      return i;
    }
  }
  return NotFound;
}

/* static */
void FullscreenRoots::Remove(Document* aDoc) {
  nsCOMPtr<Document> root = nsContentUtils::GetRootDocument(aDoc);
  uint32_t index = Find(root);
  NS_ASSERTION(index != NotFound,
               "Should only try to remove roots which are still added!");
  if (index == NotFound || !sInstance) {
    return;
  }
  sInstance->mRoots.RemoveElementAt(index);
  if (sInstance->mRoots.IsEmpty()) {
    delete sInstance;
    sInstance = nullptr;
  }
}

/* static */
bool FullscreenRoots::IsEmpty() { return !sInstance; }

// Any fullscreen change waiting for the widget to finish transition
// is queued here. This is declared static instead of a member of
// Document because in the majority of time, there would be at most
// one document requesting or exiting fullscreen. We shouldn't waste
// the space to hold for it in every document.
class PendingFullscreenChangeList {
 public:
  PendingFullscreenChangeList() = delete;

  template <typename T>
  static void Add(UniquePtr<T> aChange) {
    sList.insertBack(aChange.release());
  }

  static const FullscreenChange* GetLast() { return sList.getLast(); }

  enum IteratorOption {
    // When we are committing fullscreen changes or preparing for
    // that, we generally want to iterate all requests in the same
    // window with eDocumentsWithSameRoot option.
    eDocumentsWithSameRoot,
    // If we are removing a document from the tree, we would only
    // want to remove the requests from the given document and its
    // descendants. For that case, use eInclusiveDescendants.
    eInclusiveDescendants
  };

  template <typename T>
  class Iterator {
   public:
    explicit Iterator(Document* aDoc, IteratorOption aOption)
        : mCurrent(PendingFullscreenChangeList::sList.getFirst()),
          mRootShellForIteration(aDoc->GetDocShell()) {
      if (mCurrent) {
        if (mRootShellForIteration && aOption == eDocumentsWithSameRoot) {
          // Use a temporary to avoid undefined behavior from passing
          // mRootShellForIteration.
          nsCOMPtr<nsIDocShellTreeItem> root;
          mRootShellForIteration->GetRootTreeItem(getter_AddRefs(root));
          mRootShellForIteration = root.forget();
        }
        SkipToNextMatch();
      }
    }

    UniquePtr<T> TakeAndNext() {
      auto thisChange = TakeAndNextInternal();
      SkipToNextMatch();
      return thisChange;
    }
    bool AtEnd() const { return mCurrent == nullptr; }

   private:
    UniquePtr<T> TakeAndNextInternal() {
      FullscreenChange* thisChange = mCurrent;
      MOZ_ASSERT(thisChange->Type() == T::kType);
      mCurrent = mCurrent->removeAndGetNext();
      return WrapUnique(static_cast<T*>(thisChange));
    }
    void SkipToNextMatch() {
      while (mCurrent) {
        if (mCurrent->Type() == T::kType) {
          nsCOMPtr<nsIDocShellTreeItem> docShell =
              mCurrent->Document()->GetDocShell();
          if (!docShell) {
            // Always automatically drop fullscreen changes which are
            // from a document detached from the doc shell.
            UniquePtr<T> change = TakeAndNextInternal();
            change->MayRejectPromise();
            continue;
          }
          while (docShell && docShell != mRootShellForIteration) {
            nsCOMPtr<nsIDocShellTreeItem> parent;
            docShell->GetParent(getter_AddRefs(parent));
            docShell = parent.forget();
          }
          if (docShell) {
            break;
          }
        }
        // The current one either don't have matched type, or isn't
        // inside the given subtree, so skip this item.
        mCurrent = mCurrent->getNext();
      }
    }

    FullscreenChange* mCurrent;
    nsCOMPtr<nsIDocShellTreeItem> mRootShellForIteration;
  };

 private:
  static LinkedList<FullscreenChange> sList;
};

/* static */
LinkedList<FullscreenChange> PendingFullscreenChangeList::sList;

Document* Document::GetFullscreenRoot() {
  nsCOMPtr<Document> root = do_QueryReferent(mFullscreenRoot);
  return root;
}

void Document::SetFullscreenRoot(Document* aRoot) {
  mFullscreenRoot = do_GetWeakReference(aRoot);
}

already_AddRefed<Promise> Document::ExitFullscreen(ErrorResult& aRv) {
  UniquePtr<FullscreenExit> exit = FullscreenExit::Create(this, aRv);
  RefPtr<Promise> promise = exit->GetPromise();
  RestorePreviousFullscreenState(std::move(exit));
  return promise.forget();
}

static void AskWindowToExitFullscreen(Document* aDoc) {
  if (XRE_GetProcessType() == GeckoProcessType_Content) {
    nsContentUtils::DispatchEventOnlyToChrome(
        aDoc, ToSupports(aDoc), NS_LITERAL_STRING("MozDOMFullscreen:Exit"),
        CanBubble::eYes, Cancelable::eNo, /* DefaultAction */ nullptr);
  } else {
    if (nsPIDOMWindowOuter* win = aDoc->GetWindow()) {
      win->SetFullscreenInternal(FullscreenReason::ForFullscreenAPI, false);
    }
  }
}

class nsCallExitFullscreen : public Runnable {
 public:
  explicit nsCallExitFullscreen(Document* aDoc)
      : mozilla::Runnable("nsCallExitFullscreen"), mDoc(aDoc) {}

  NS_IMETHOD Run() final {
    if (!mDoc) {
      FullscreenRoots::ForEach(&AskWindowToExitFullscreen);
    } else {
      AskWindowToExitFullscreen(mDoc);
    }
    return NS_OK;
  }

 private:
  nsCOMPtr<Document> mDoc;
};

/* static */
void Document::AsyncExitFullscreen(Document* aDoc) {
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  nsCOMPtr<nsIRunnable> exit = new nsCallExitFullscreen(aDoc);
  if (aDoc) {
    aDoc->Dispatch(TaskCategory::Other, exit.forget());
  } else {
    NS_DispatchToCurrentThread(exit.forget());
  }
}

static bool CountFullscreenSubDocuments(Document* aDoc, void* aData) {
  if (aDoc->FullscreenStackTop()) {
    uint32_t* count = static_cast<uint32_t*>(aData);
    (*count)++;
  }
  return true;
}

static uint32_t CountFullscreenSubDocuments(Document* aDoc) {
  uint32_t count = 0;
  aDoc->EnumerateSubDocuments(CountFullscreenSubDocuments, &count);
  return count;
}

bool Document::IsFullscreenLeaf() {
  // A fullscreen leaf document is fullscreen, and has no fullscreen
  // subdocuments.
  if (!FullscreenStackTop()) {
    return false;
  }
  return CountFullscreenSubDocuments(this) == 0;
}

bool GetFullscreenLeaf(Document* aDoc, void* aData) {
  if (aDoc->IsFullscreenLeaf()) {
    Document** result = static_cast<Document**>(aData);
    *result = aDoc;
    return false;
  }
  if (aDoc->FullscreenStackTop()) {
    aDoc->EnumerateSubDocuments(GetFullscreenLeaf, aData);
  }
  return true;
}

static Document* GetFullscreenLeaf(Document* aDoc) {
  Document* leaf = nullptr;
  GetFullscreenLeaf(aDoc, &leaf);
  if (leaf) {
    return leaf;
  }
  // Otherwise we could be either in a non-fullscreen doc tree, or we're
  // below the fullscreen doc. Start the search from the root.
  Document* root = nsContentUtils::GetRootDocument(aDoc);
  // Check that the root is actually fullscreen so we don't waste time walking
  // around its descendants.
  if (!root->FullscreenStackTop()) {
    return nullptr;
  }
  GetFullscreenLeaf(root, &leaf);
  return leaf;
}

static bool ResetFullscreen(Document* aDocument, void* aData) {
  if (Element* fsElement = aDocument->FullscreenStackTop()) {
    NS_ASSERTION(CountFullscreenSubDocuments(aDocument) <= 1,
                 "Should have at most 1 fullscreen subdocument.");
    aDocument->CleanupFullscreenState();
    NS_ASSERTION(!aDocument->FullscreenStackTop(), "Should reset fullscreen");
    DispatchFullscreenChange(aDocument, fsElement);
    aDocument->EnumerateSubDocuments(ResetFullscreen, nullptr);
  }
  return true;
}

// Since Document::ExitFullscreenInDocTree() could be called from
// Element::UnbindFromTree() where it is not safe to synchronously run
// script. This runnable is the script part of that function.
class ExitFullscreenScriptRunnable : public Runnable {
 public:
  explicit ExitFullscreenScriptRunnable(Document* aRoot, Document* aLeaf)
      : mozilla::Runnable("ExitFullscreenScriptRunnable"),
        mRoot(aRoot),
        mLeaf(aLeaf) {}

  NS_IMETHOD Run() override {
    // Dispatch MozDOMFullscreen:Exited to the original fullscreen leaf
    // document since we want this event to follow the same path that
    // MozDOMFullscreen:Entered was dispatched.
    nsContentUtils::DispatchEventOnlyToChrome(
        mLeaf, ToSupports(mLeaf), NS_LITERAL_STRING("MozDOMFullscreen:Exited"),
        CanBubble::eYes, Cancelable::eNo, /* DefaultAction */ nullptr);
    // Ensure the window exits fullscreen.
    if (nsPIDOMWindowOuter* win = mRoot->GetWindow()) {
      win->SetFullscreenInternal(FullscreenReason::ForForceExitFullscreen,
                                 false);
    }
    return NS_OK;
  }

 private:
  nsCOMPtr<Document> mRoot;
  nsCOMPtr<Document> mLeaf;
};

/* static */
void Document::ExitFullscreenInDocTree(Document* aMaybeNotARootDoc) {
  MOZ_ASSERT(aMaybeNotARootDoc);

  // Unlock the pointer
  UnlockPointer();

  // Resolve all promises which waiting for exit fullscreen.
  PendingFullscreenChangeList::Iterator<FullscreenExit> iter(
      aMaybeNotARootDoc, PendingFullscreenChangeList::eDocumentsWithSameRoot);
  while (!iter.AtEnd()) {
    UniquePtr<FullscreenExit> exit = iter.TakeAndNext();
    exit->MayResolvePromise();
  }

  nsCOMPtr<Document> root = aMaybeNotARootDoc->GetFullscreenRoot();
  if (!root || !root->FullscreenStackTop()) {
    // If a document was detached before exiting from fullscreen, it is
    // possible that the root had left fullscreen state. In this case,
    // we would not get anything from the ResetFullscreen() call. Root's
    // not being a fullscreen doc also means the widget should have
    // exited fullscreen state. It means even if we do not return here,
    // we would actually do nothing below except crashing ourselves via
    // dispatching the "MozDOMFullscreen:Exited" event to an nonexistent
    // document.
    return;
  }

  // Record the fullscreen leaf document for MozDOMFullscreen:Exited.
  // See ExitFullscreenScriptRunnable::Run for details. We have to
  // record it here because we don't have such information after we
  // reset the fullscreen state below.
  Document* fullscreenLeaf = GetFullscreenLeaf(root);

  // Walk the tree of fullscreen documents, and reset their fullscreen state.
  ResetFullscreen(root, nullptr);

  NS_ASSERTION(!root->FullscreenStackTop(),
               "Fullscreen root should no longer be a fullscreen doc...");

  // Move the top-level window out of fullscreen mode.
  FullscreenRoots::Remove(root);

  nsContentUtils::AddScriptRunner(
      new ExitFullscreenScriptRunnable(root, fullscreenLeaf));
}

static void DispatchFullscreenNewOriginEvent(Document* aDoc) {
  RefPtr<AsyncEventDispatcher> asyncDispatcher = new AsyncEventDispatcher(
      aDoc, NS_LITERAL_STRING("MozDOMFullscreen:NewOrigin"), CanBubble::eYes,
      ChromeOnlyDispatch::eYes);
  asyncDispatcher->PostDOMEvent();
}

void Document::RestorePreviousFullscreenState(UniquePtr<FullscreenExit> aExit) {
  NS_ASSERTION(!FullscreenStackTop() || !FullscreenRoots::IsEmpty(),
               "Should have at least 1 fullscreen root when fullscreen!");

  if (!FullscreenStackTop() || !GetWindow() || FullscreenRoots::IsEmpty()) {
    aExit->MayRejectPromise();
    return;
  }

  nsCOMPtr<Document> fullScreenDoc = GetFullscreenLeaf(this);
  AutoTArray<Element*, 8> exitElements;

  Document* doc = fullScreenDoc;
  // Collect all subdocuments.
  for (; doc != this; doc = doc->GetParentDocument()) {
    Element* fsElement = doc->FullscreenStackTop();
    MOZ_ASSERT(fsElement,
               "Parent document of "
               "a fullscreen document without fullscreen element?");
    exitElements.AppendElement(fsElement);
  }
  MOZ_ASSERT(doc == this, "Must have reached this doc");
  // Collect all ancestor documents which we are going to change.
  for (; doc; doc = doc->GetParentDocument()) {
    MOZ_ASSERT(!doc->mFullscreenStack.IsEmpty(),
               "Ancestor of fullscreen document must also be in fullscreen");
    Element* fsElement = doc->FullscreenStackTop();
    if (doc != this) {
      if (auto* iframe = HTMLIFrameElement::FromNode(fsElement)) {
        if (iframe->FullscreenFlag()) {
          // If this is an iframe, and it explicitly requested
          // fullscreen, don't rollback it automatically.
          break;
        }
      }
    }
    exitElements.AppendElement(fsElement);
    if (doc->mFullscreenStack.Length() > 1) {
      break;
    }
  }

  Document* lastDoc = exitElements.LastElement()->OwnerDoc();
  if (!lastDoc->GetParentDocument() &&
      lastDoc->mFullscreenStack.Length() == 1) {
    // If we are fully exiting fullscreen, don't touch anything here,
    // just wait for the window to get out from fullscreen first.
    PendingFullscreenChangeList::Add(std::move(aExit));
    AskWindowToExitFullscreen(this);
    return;
  }

  // If fullscreen mode is updated the pointer should be unlocked
  UnlockPointer();
  // All documents listed in the array except the last one are going to
  // completely exit from the fullscreen state.
  for (auto i : IntegerRange(exitElements.Length() - 1)) {
    exitElements[i]->OwnerDoc()->CleanupFullscreenState();
  }
  // The last document will either rollback one fullscreen element, or
  // completely exit from the fullscreen state as well.
  Document* newFullscreenDoc;
  if (lastDoc->mFullscreenStack.Length() > 1) {
    lastDoc->FullscreenStackPop();
    newFullscreenDoc = lastDoc;
  } else {
    lastDoc->CleanupFullscreenState();
    newFullscreenDoc = lastDoc->GetParentDocument();
  }
  // Dispatch the fullscreenchange event to all document listed. Note
  // that the loop order is reversed so that events are dispatched in
  // the tree order as indicated in the spec.
  for (Element* e : Reversed(exitElements)) {
    DispatchFullscreenChange(e->OwnerDoc(), e);
  }
  aExit->MayResolvePromise();

  MOZ_ASSERT(newFullscreenDoc,
             "If we were going to exit from fullscreen on "
             "all documents in this doctree, we should've asked the window to "
             "exit first instead of reaching here.");
  if (fullScreenDoc != newFullscreenDoc &&
      !nsContentUtils::HaveEqualPrincipals(fullScreenDoc, newFullscreenDoc)) {
    // We've popped so enough off the stack that we've rolled back to
    // a fullscreen element in a parent document. If this document is
    // cross origin, dispatch an event to chrome so it knows to show
    // the warning UI.
    DispatchFullscreenNewOriginEvent(newFullscreenDoc);
  }
}

class nsCallRequestFullscreen : public Runnable {
 public:
  explicit nsCallRequestFullscreen(UniquePtr<FullscreenRequest> aRequest)
      : mozilla::Runnable("nsCallRequestFullscreen"),
        mRequest(std::move(aRequest)) {}

  NS_IMETHOD Run() override {
    Document* doc = mRequest->Document();
    doc->RequestFullscreen(std::move(mRequest));
    return NS_OK;
  }

  UniquePtr<FullscreenRequest> mRequest;
};

void Document::AsyncRequestFullscreen(UniquePtr<FullscreenRequest> aRequest) {
  // Request fullscreen asynchronously.
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  nsCOMPtr<nsIRunnable> event =
      new nsCallRequestFullscreen(std::move(aRequest));
  Dispatch(TaskCategory::Other, event.forget());
}

static void UpdateViewportScrollbarOverrideForFullscreen(Document* aDoc) {
  if (nsPresContext* presContext = aDoc->GetPresContext()) {
    presContext->UpdateViewportScrollStylesOverride();
  }
}

static void ClearFullscreenStateOnElement(Element* aElement) {
  // Remove styles from existing top element.
  EventStateManager::SetFullscreenState(aElement, false);
  // Reset iframe fullscreen flag.
  if (aElement->IsHTMLElement(nsGkAtoms::iframe)) {
    static_cast<HTMLIFrameElement*>(aElement)->SetFullscreenFlag(false);
  }
}

void Document::CleanupFullscreenState() {
  // Iterate the fullscreen stack and clear the fullscreen states.
  // Since we also need to clear the fullscreen-ancestor state, and
  // currently fullscreen elements can only be placed in hierarchy
  // order in the stack, reversely iterating the stack could be more
  // efficient. NOTE that fullscreen-ancestor state would be removed
  // in bug 1199529, and the elements may not in hierarchy order
  // after bug 1195213.
  for (nsWeakPtr& weakPtr : Reversed(mFullscreenStack)) {
    if (nsCOMPtr<Element> element = do_QueryReferent(weakPtr)) {
      ClearFullscreenStateOnElement(element);
    }
  }
  mFullscreenStack.Clear();
  mFullscreenRoot = nullptr;

  // Restore the zoom level that was in place prior to entering fullscreen.
  if (PresShell* presShell = GetPresShell()) {
    if (presShell->GetMobileViewportManager()) {
      presShell->SetResolutionAndScaleTo(mSavedResolution,
                                         ResolutionChangeOrigin::MainThread);
    }
  }

  UpdateViewportScrollbarOverrideForFullscreen(this);
}

bool Document::FullscreenStackPush(Element* aElement) {
  NS_ASSERTION(aElement, "Must pass non-null to FullscreenStackPush()");
  Element* top = FullscreenStackTop();
  if (top == aElement || !aElement) {
    return false;
  }
  EventStateManager::SetFullscreenState(aElement, true);
  mFullscreenStack.AppendElement(do_GetWeakReference(aElement));
  NS_ASSERTION(FullscreenStackTop() == aElement, "Should match");
  UpdateViewportScrollbarOverrideForFullscreen(this);
  return true;
}

void Document::FullscreenStackPop() {
  if (mFullscreenStack.IsEmpty()) {
    return;
  }

  ClearFullscreenStateOnElement(FullscreenStackTop());

  // Remove top element. Note the remaining top element in the stack
  // will not have fullscreen style bits set, so we will need to restore
  // them on the new top element before returning.
  uint32_t last = mFullscreenStack.Length() - 1;
  mFullscreenStack.RemoveElementAt(last);

  // Pop from the stack null elements (references to elements which have
  // been GC'd since they were added to the stack) and elements which are
  // no longer in this document.
  while (!mFullscreenStack.IsEmpty()) {
    Element* element = FullscreenStackTop();
    if (!element || !element->IsInUncomposedDoc() ||
        element->OwnerDoc() != this) {
      NS_ASSERTION(!element->State().HasState(NS_EVENT_STATE_FULLSCREEN),
                   "Should have already removed fullscreen styles");
      uint32_t last = mFullscreenStack.Length() - 1;
      mFullscreenStack.RemoveElementAt(last);
    } else {
      // The top element of the stack is now an in-doc element. Return here.
      break;
    }
  }

  UpdateViewportScrollbarOverrideForFullscreen(this);
}

Element* Document::FullscreenStackTop() {
  if (mFullscreenStack.IsEmpty()) {
    return nullptr;
  }
  uint32_t last = mFullscreenStack.Length() - 1;
  nsCOMPtr<Element> element(do_QueryReferent(mFullscreenStack[last]));
  NS_ASSERTION(element, "Should have fullscreen element!");
  NS_ASSERTION(element->IsInComposedDoc(),
               "Fullscreen element should be in doc");
  NS_ASSERTION(element->OwnerDoc() == this,
               "Fullscreen element should be in this doc");
  return element;
}

nsTArray<Element*> Document::GetFullscreenStack() const {
  nsTArray<Element*> elements;
  for (const nsWeakPtr& ptr : mFullscreenStack) {
    if (nsCOMPtr<Element> elem = do_QueryReferent(ptr)) {
      MOZ_ASSERT(elem->State().HasState(NS_EVENT_STATE_FULLSCREEN));
      elements.AppendElement(elem);
    }
  }
  return elements;
}

// Returns true if aDoc is in the focused tab in the active window.
static bool IsInActiveTab(Document* aDoc) {
  nsCOMPtr<nsIDocShell> docshell = aDoc->GetDocShell();
  if (!docshell) {
    return false;
  }

  bool isActive = false;
  docshell->GetIsActive(&isActive);
  if (!isActive) {
    return false;
  }

  nsCOMPtr<nsIDocShellTreeItem> rootItem;
  docshell->GetRootTreeItem(getter_AddRefs(rootItem));
  if (!rootItem) {
    return false;
  }
  nsCOMPtr<nsPIDOMWindowOuter> rootWin = rootItem->GetWindow();
  if (!rootWin) {
    return false;
  }

  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  if (!fm) {
    return false;
  }

  nsCOMPtr<mozIDOMWindowProxy> activeWindow;
  fm->GetActiveWindow(getter_AddRefs(activeWindow));
  if (!activeWindow) {
    return false;
  }

  return activeWindow == rootWin;
}

nsresult Document::RemoteFrameFullscreenChanged(Element* aFrameElement) {
  // Ensure the frame element is the fullscreen element in this document.
  // If the frame element is already the fullscreen element in this document,
  // this has no effect.
  auto request = FullscreenRequest::CreateForRemote(aFrameElement);
  RequestFullscreen(std::move(request));
  return NS_OK;
}

nsresult Document::RemoteFrameFullscreenReverted() {
  UniquePtr<FullscreenExit> exit = FullscreenExit::CreateForRemote(this);
  RestorePreviousFullscreenState(std::move(exit));
  return NS_OK;
}

/* static */
bool Document::IsUnprefixedFullscreenEnabled(JSContext* aCx,
                                             JSObject* aObject) {
  MOZ_ASSERT(NS_IsMainThread());
  return nsContentUtils::IsSystemCaller(aCx) ||
         StaticPrefs::full_screen_api_unprefix_enabled();
}

static bool HasFullscreenSubDocument(Document* aDoc) {
  uint32_t count = CountFullscreenSubDocuments(aDoc);
  NS_ASSERTION(count <= 1,
               "Fullscreen docs should have at most 1 fullscreen child!");
  return count >= 1;
}

// Returns nullptr if a request for Fullscreen API is currently enabled
// in the given document. Returns a static string indicates the reason
// why it is not enabled otherwise.
static const char* GetFullscreenError(Document* aDoc, CallerType aCallerType) {
  bool apiEnabled = StaticPrefs::full_screen_api_enabled();
  if (apiEnabled && aCallerType == CallerType::System) {
    // Chrome code can always use the fullscreen API, provided it's not
    // explicitly disabled.
    return nullptr;
  }

  if (!apiEnabled) {
    return "FullscreenDeniedDisabled";
  }

  if (!aDoc->IsVisible()) {
    return "FullscreenDeniedHidden";
  }

  // Ensure that all containing elements are <iframe> and have
  // allowfullscreen attribute set.
  nsCOMPtr<nsIDocShell> docShell(aDoc->GetDocShell());
  if (!docShell || !docShell->GetFullscreenAllowed()) {
    return "FullscreenDeniedContainerNotAllowed";
  }
  return nullptr;
}

bool Document::FullscreenElementReadyCheck(const FullscreenRequest& aRequest) {
  Element* elem = aRequest.Element();
  // Strictly speaking, this isn't part of the fullscreen element ready
  // check in the spec, but per steps in the spec, when an element which
  // is already the fullscreen element requests fullscreen, nothing
  // should change and no event should be dispatched, but we still need
  // to resolve the returned promise.
  if (elem == FullscreenStackTop()) {
    aRequest.MayResolvePromise();
    return false;
  }
  if (!elem->IsInComposedDoc()) {
    aRequest.Reject("FullscreenDeniedNotInDocument");
    return false;
  }
  if (elem->OwnerDoc() != this) {
    aRequest.Reject("FullscreenDeniedMovedDocument");
    return false;
  }
  if (!GetWindow()) {
    aRequest.Reject("FullscreenDeniedLostWindow");
    return false;
  }
  if (const char* msg = GetFullscreenError(this, aRequest.mCallerType)) {
    aRequest.Reject(msg);
    return false;
  }
  if (HasFullscreenSubDocument(this)) {
    aRequest.Reject("FullscreenDeniedSubDocFullScreen");
    return false;
  }
  // XXXsmaug Note, we don't follow the latest fullscreen spec here.
  //         This whole check could be probably removed.
  if (FullscreenStackTop() &&
      !nsContentUtils::ContentIsHostIncludingDescendantOf(
          elem, FullscreenStackTop())) {
    // If this document is fullscreen, only grant fullscreen requests from
    // a descendant of the current fullscreen element.
    aRequest.Reject("FullscreenDeniedNotDescendant");
    return false;
  }
  if (!nsContentUtils::IsChromeDoc(this) && !IsInActiveTab(this)) {
    aRequest.Reject("FullscreenDeniedNotFocusedTab");
    return false;
  }
  // Deny requests when a windowed plugin is focused.
  nsFocusManager* fm = nsFocusManager::GetFocusManager();
  if (!fm) {
    NS_WARNING("Failed to retrieve focus manager in fullscreen request.");
    aRequest.MayRejectPromise();
    return false;
  }
  if (nsContentUtils::HasPluginWithUncontrolledEventDispatch(
          fm->GetFocusedElement())) {
    aRequest.Reject("FullscreenDeniedFocusedPlugin");
    return false;
  }
  return true;
}

static nsCOMPtr<nsPIDOMWindowOuter> GetRootWindow(Document* aDoc) {
  nsIDocShell* docShell = aDoc->GetDocShell();
  if (!docShell) {
    return nullptr;
  }
  nsCOMPtr<nsIDocShellTreeItem> rootItem;
  docShell->GetRootTreeItem(getter_AddRefs(rootItem));
  return rootItem ? rootItem->GetWindow() : nullptr;
}

static bool ShouldApplyFullscreenDirectly(Document* aDoc,
                                          nsPIDOMWindowOuter* aRootWin) {
  if (XRE_GetProcessType() == GeckoProcessType_Content) {
    // If we are in the content process, we can apply the fullscreen
    // state directly only if we have been in DOM fullscreen, because
    // otherwise we always need to notify the chrome.
    return !!nsContentUtils::GetRootDocument(aDoc)->GetFullscreenElement();
  } else {
    // If we are in the chrome process, and the window has not been in
    // fullscreen, we certainly need to make that fullscreen first.
    if (!aRootWin->GetFullScreen()) {
      return false;
    }
    // The iterator not being at end indicates there is still some
    // pending fullscreen request relates to this document. We have to
    // push the request to the pending queue so requests are handled
    // in the correct order.
    PendingFullscreenChangeList::Iterator<FullscreenRequest> iter(
        aDoc, PendingFullscreenChangeList::eDocumentsWithSameRoot);
    if (!iter.AtEnd()) {
      return false;
    }
    // We have to apply the fullscreen state directly in this case,
    // because nsGlobalWindow::SetFullscreenInternal() will do nothing
    // if it is already in fullscreen. If we do not apply the state but
    // instead add it to the queue and wait for the window as normal,
    // we would get stuck.
    return true;
  }
}

void Document::RequestFullscreen(UniquePtr<FullscreenRequest> aRequest) {
  nsCOMPtr<nsPIDOMWindowOuter> rootWin = GetRootWindow(this);
  if (!rootWin) {
    aRequest->MayRejectPromise();
    return;
  }

  if (ShouldApplyFullscreenDirectly(this, rootWin)) {
    ApplyFullscreen(std::move(aRequest));
    return;
  }

  // Per spec only HTML, <svg>, and <math> should be allowed, but
  // we also need to allow XUL elements right now.
  Element* elem = aRequest->Element();
  if (!elem->IsHTMLElement() && !elem->IsXULElement() &&
      !elem->IsSVGElement(nsGkAtoms::svg) &&
      !elem->IsMathMLElement(nsGkAtoms::math)) {
    aRequest->Reject("FullscreenDeniedNotHTMLSVGOrMathML");
    return;
  }

  // We don't need to check element ready before this point, because
  // if we called ApplyFullscreen, it would check that for us.
  if (!FullscreenElementReadyCheck(*aRequest)) {
    return;
  }

  PendingFullscreenChangeList::Add(std::move(aRequest));
  if (XRE_GetProcessType() == GeckoProcessType_Content) {
    // If we are not the top level process, dispatch an event to make
    // our parent process go fullscreen first.
    nsContentUtils::DispatchEventOnlyToChrome(
        this, ToSupports(this), NS_LITERAL_STRING("MozDOMFullscreen:Request"),
        CanBubble::eYes, Cancelable::eNo, /* DefaultAction */ nullptr);
  } else {
    // Make the window fullscreen.
    rootWin->SetFullscreenInternal(FullscreenReason::ForFullscreenAPI, true);
  }
}

/* static */
bool Document::HandlePendingFullscreenRequests(Document* aDoc) {
  bool handled = false;
  PendingFullscreenChangeList::Iterator<FullscreenRequest> iter(
      aDoc, PendingFullscreenChangeList::eDocumentsWithSameRoot);
  while (!iter.AtEnd()) {
    UniquePtr<FullscreenRequest> request = iter.TakeAndNext();
    Document* doc = request->Document();
    if (doc->ApplyFullscreen(std::move(request))) {
      handled = true;
    }
  }
  return handled;
}

static void ClearPendingFullscreenRequests(Document* aDoc) {
  PendingFullscreenChangeList::Iterator<FullscreenRequest> iter(
      aDoc, PendingFullscreenChangeList::eInclusiveDescendants);
  while (!iter.AtEnd()) {
    UniquePtr<FullscreenRequest> request = iter.TakeAndNext();
    request->MayRejectPromise();
  }
}

bool Document::ApplyFullscreen(UniquePtr<FullscreenRequest> aRequest) {
  if (!FullscreenElementReadyCheck(*aRequest)) {
    return false;
  }

  // Stash a reference to any existing fullscreen doc, we'll use this later
  // to detect if the origin which is fullscreen has changed.
  nsCOMPtr<Document> previousFullscreenDoc = GetFullscreenLeaf(this);

  // Stores a list of documents which we must dispatch "fullscreenchange"
  // too. We're required by the spec to dispatch the events in root-to-leaf
  // order, but we traverse the doctree in a leaf-to-root order, so we save
  // references to the documents we must dispatch to so that we get the order
  // as specified.
  AutoTArray<Document*, 8> changed;

  // Remember the root document, so that if a fullscreen document is hidden
  // we can reset fullscreen state in the remaining visible fullscreen
  // documents.
  Document* fullScreenRootDoc = nsContentUtils::GetRootDocument(this);

  // If a document is already in fullscreen, then unlock the mouse pointer
  // before setting a new document to fullscreen
  UnlockPointer();

  // Set the fullscreen element. This sets the fullscreen style on the
  // element, and the fullscreen-ancestor styles on ancestors of the element
  // in this document.
  Element* elem = aRequest->Element();
  DebugOnly<bool> x = FullscreenStackPush(elem);
  NS_ASSERTION(x, "Fullscreen state of requesting doc should always change!");
  // Set the iframe fullscreen flag.
  if (auto* iframe = HTMLIFrameElement::FromNode(elem)) {
    iframe->SetFullscreenFlag(true);
  }
  changed.AppendElement(this);

  // Propagate up the document hierarchy, setting the fullscreen element as
  // the element's container in ancestor documents. This also sets the
  // appropriate css styles as well. Note we don't propagate down the
  // document hierarchy, the fullscreen element (or its container) is not
  // visible there. Stop when we reach the root document.
  Document* child = this;
  while (true) {
    child->SetFullscreenRoot(fullScreenRootDoc);

    // When entering fullscreen, reset the RCD's resolution to the intrinsic
    // resolution, otherwise the fullscreen content could be sized larger than
    // the screen (since fullscreen is implemented using position:fixed and
    // fixed elements are sized to the layout viewport).
    // This also ensures that things like video controls aren't zoomed in
    // when in fullscreen mode.
    if (PresShell* presShell = child->GetPresShell()) {
      if (RefPtr<MobileViewportManager> manager =
              presShell->GetMobileViewportManager()) {
        // Save the previous resolution so it can be restored.
        child->mSavedResolution = presShell->GetResolution();
        presShell->SetResolutionAndScaleTo(
            manager->ComputeIntrinsicResolution(),
            ResolutionChangeOrigin::MainThread);
      }
    }

    NS_ASSERTION(child->GetFullscreenRoot() == fullScreenRootDoc,
                 "Fullscreen root should be set!");
    if (child == fullScreenRootDoc) {
      break;
    }
    Document* parent = child->GetParentDocument();
    Element* element = parent->FindContentForSubDocument(child);
    if (parent->FullscreenStackPush(element)) {
      changed.AppendElement(parent);
      child = parent;
    } else {
      // We've reached either the root, or a point in the doctree where the
      // new fullscreen element container is the same as the previous
      // fullscreen element's container. No more changes need to be made
      // to the fullscreen stacks of documents further up the tree.
      break;
    }
  }

  FullscreenRoots::Add(this);

  // If it is the first entry of the fullscreen, trigger an event so
  // that the UI can response to this change, e.g. hide chrome, or
  // notifying parent process to enter fullscreen. Note that chrome
  // code may also want to listen to MozDOMFullscreen:NewOrigin event
  // to pop up warning UI.
  if (!previousFullscreenDoc) {
    nsContentUtils::DispatchEventOnlyToChrome(
        this, ToSupports(elem), NS_LITERAL_STRING("MozDOMFullscreen:Entered"),
        CanBubble::eYes, Cancelable::eNo, /* DefaultAction */ nullptr);
  }

  // The origin which is fullscreen gets changed. Trigger an event so
  // that the chrome knows to pop up a warning UI. Note that
  // previousFullscreenDoc == nullptr upon first entry, so we always
  // take this path on the first entry. Also note that, in a multi-
  // process browser, the code in content process is responsible for
  // sending message with the origin to its parent, and the parent
  // shouldn't rely on this event itself.
  if (aRequest->mShouldNotifyNewOrigin &&
      !nsContentUtils::HaveEqualPrincipals(previousFullscreenDoc, this)) {
    DispatchFullscreenNewOriginEvent(this);
  }

  // Dispatch "fullscreenchange" events. Note that the loop order is
  // reversed so that events are dispatched in the tree order as
  // indicated in the spec.
  for (Document* d : Reversed(changed)) {
    DispatchFullscreenChange(d, d->FullscreenStackTop());
  }
  aRequest->MayResolvePromise();
  return true;
}

bool Document::FullscreenEnabled(CallerType aCallerType) {
  return !GetFullscreenError(this, aCallerType);
}

void Document::SetOrientationPendingPromise(Promise* aPromise) {
  mOrientationPendingPromise = aPromise;
}

static void DispatchPointerLockChange(Document* aTarget) {
  if (!aTarget) {
    return;
  }

  RefPtr<AsyncEventDispatcher> asyncDispatcher =
      new AsyncEventDispatcher(aTarget, NS_LITERAL_STRING("pointerlockchange"),
                               CanBubble::eYes, ChromeOnlyDispatch::eNo);
  asyncDispatcher->PostDOMEvent();
}

static void DispatchPointerLockError(Document* aTarget, const char* aMessage) {
  if (!aTarget) {
    return;
  }

  RefPtr<AsyncEventDispatcher> asyncDispatcher =
      new AsyncEventDispatcher(aTarget, NS_LITERAL_STRING("pointerlockerror"),
                               CanBubble::eYes, ChromeOnlyDispatch::eNo);
  asyncDispatcher->PostDOMEvent();
  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                  NS_LITERAL_CSTRING("DOM"), aTarget,
                                  nsContentUtils::eDOM_PROPERTIES, aMessage);
}

class PointerLockRequest final : public Runnable {
 public:
  PointerLockRequest(Element* aElement, bool aUserInputOrChromeCaller)
      : mozilla::Runnable("PointerLockRequest"),
        mElement(do_GetWeakReference(aElement)),
        mDocument(do_GetWeakReference(aElement->OwnerDoc())),
        mUserInputOrChromeCaller(aUserInputOrChromeCaller) {}

  MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHOD Run() final;

 private:
  nsWeakPtr mElement;
  nsWeakPtr mDocument;
  bool mUserInputOrChromeCaller;
};

static const char* GetPointerLockError(Element* aElement, Element* aCurrentLock,
                                       bool aNoFocusCheck = false) {
  // Check if pointer lock pref is enabled
  if (!Preferences::GetBool("full-screen-api.pointer-lock.enabled")) {
    return "PointerLockDeniedDisabled";
  }

  nsCOMPtr<Document> ownerDoc = aElement->OwnerDoc();
  if (aCurrentLock && aCurrentLock->OwnerDoc() != ownerDoc) {
    return "PointerLockDeniedInUse";
  }

  if (!aElement->IsInComposedDoc()) {
    return "PointerLockDeniedNotInDocument";
  }

  if (ownerDoc->GetSandboxFlags() & SANDBOXED_POINTER_LOCK) {
    return "PointerLockDeniedSandboxed";
  }

  // Check if the element is in a document with a docshell.
  if (!ownerDoc->GetContainer()) {
    return "PointerLockDeniedHidden";
  }
  nsCOMPtr<nsPIDOMWindowOuter> ownerWindow = ownerDoc->GetWindow();
  if (!ownerWindow) {
    return "PointerLockDeniedHidden";
  }
  nsCOMPtr<nsPIDOMWindowInner> ownerInnerWindow = ownerDoc->GetInnerWindow();
  if (!ownerInnerWindow) {
    return "PointerLockDeniedHidden";
  }
  if (ownerWindow->GetCurrentInnerWindow() != ownerInnerWindow) {
    return "PointerLockDeniedHidden";
  }

  nsCOMPtr<nsPIDOMWindowOuter> top = ownerWindow->GetScriptableTop();
  if (!top || !top->GetExtantDoc() || top->GetExtantDoc()->Hidden()) {
    return "PointerLockDeniedHidden";
  }

  if (!aNoFocusCheck) {
    mozilla::ErrorResult rv;
    if (!top->GetExtantDoc()->HasFocus(rv)) {
      return "PointerLockDeniedNotFocused";
    }
  }

  return nullptr;
}

static void ChangePointerLockedElement(Element* aElement, Document* aDocument,
                                       Element* aPointerLockedElement) {
  // aDocument here is not really necessary, as it is the uncomposed
  // document of both aElement and aPointerLockedElement as far as one
  // is not nullptr, and they wouldn't both be nullptr in any case.
  // But since the caller of this function should have known what the
  // document is, we just don't try to figure out what it should be.
  MOZ_ASSERT(aDocument);
  MOZ_ASSERT(aElement != aPointerLockedElement);
  if (aPointerLockedElement) {
    MOZ_ASSERT(aPointerLockedElement->GetComposedDoc() == aDocument);
    aPointerLockedElement->ClearPointerLock();
  }
  if (aElement) {
    MOZ_ASSERT(aElement->GetComposedDoc() == aDocument);
    aElement->SetPointerLock();
    EventStateManager::sPointerLockedElement = do_GetWeakReference(aElement);
    EventStateManager::sPointerLockedDoc = do_GetWeakReference(aDocument);
    NS_ASSERTION(EventStateManager::sPointerLockedElement &&
                     EventStateManager::sPointerLockedDoc,
                 "aElement and this should support weak references!");
  } else {
    EventStateManager::sPointerLockedElement = nullptr;
    EventStateManager::sPointerLockedDoc = nullptr;
  }
  // Retarget all events to aElement via capture or
  // stop retargeting if aElement is nullptr.
  PresShell::SetCapturingContent(aElement, CaptureFlags::PointerLock);
  DispatchPointerLockChange(aDocument);
}

NS_IMETHODIMP
PointerLockRequest::Run() {
  nsCOMPtr<Element> e = do_QueryReferent(mElement);
  nsCOMPtr<Document> doc = do_QueryReferent(mDocument);
  const char* error = nullptr;
  if (!e || !doc || !e->GetComposedDoc()) {
    error = "PointerLockDeniedNotInDocument";
  } else if (e->GetComposedDoc() != doc) {
    error = "PointerLockDeniedMovedDocument";
  }
  if (!error) {
    nsCOMPtr<Element> pointerLockedElement =
        do_QueryReferent(EventStateManager::sPointerLockedElement);
    if (e == pointerLockedElement) {
      DispatchPointerLockChange(doc);
      return NS_OK;
    }
    // Note, we must bypass focus change, so pass true as the last parameter!
    error = GetPointerLockError(e, pointerLockedElement, true);
    // Another element in the same document is requesting pointer lock,
    // just grant it without user input check.
    if (!error && pointerLockedElement) {
      ChangePointerLockedElement(e, doc, pointerLockedElement);
      return NS_OK;
    }
  }
  // If it is neither user input initiated, nor requested in fullscreen,
  // it should be rejected.
  if (!error && !mUserInputOrChromeCaller && !doc->GetFullscreenElement()) {
    error = "PointerLockDeniedNotInputDriven";
  }
  if (!error && !doc->SetPointerLock(e, StyleCursorKind::None)) {
    error = "PointerLockDeniedFailedToLock";
  }
  if (error) {
    DispatchPointerLockError(doc, error);
    return NS_OK;
  }

  ChangePointerLockedElement(e, doc, nullptr);
  nsContentUtils::DispatchEventOnlyToChrome(
      doc, ToSupports(e), NS_LITERAL_STRING("MozDOMPointerLock:Entered"),
      CanBubble::eYes, Cancelable::eNo, /* DefaultAction */ nullptr);
  return NS_OK;
}

void Document::RequestPointerLock(Element* aElement, CallerType aCallerType) {
  NS_ASSERTION(aElement,
               "Must pass non-null element to Document::RequestPointerLock");

  nsCOMPtr<Element> pointerLockedElement =
      do_QueryReferent(EventStateManager::sPointerLockedElement);
  if (aElement == pointerLockedElement) {
    DispatchPointerLockChange(this);
    return;
  }

  if (const char* msg = GetPointerLockError(aElement, pointerLockedElement)) {
    DispatchPointerLockError(this, msg);
    return;
  }

  bool userInputOrSystemCaller = EventStateManager::IsHandlingUserInput() ||
                                 aCallerType == CallerType::System;
  nsCOMPtr<nsIRunnable> request =
      new PointerLockRequest(aElement, userInputOrSystemCaller);
  Dispatch(TaskCategory::Other, request.forget());
}

bool Document::SetPointerLock(Element* aElement, StyleCursorKind aCursorStyle) {
  MOZ_ASSERT(!aElement || aElement->OwnerDoc() == this,
             "We should be either unlocking pointer (aElement is nullptr), "
             "or locking pointer to an element in this document");
#ifdef DEBUG
  if (!aElement) {
    nsCOMPtr<Document> pointerLockedDoc =
        do_QueryReferent(EventStateManager::sPointerLockedDoc);
    MOZ_ASSERT(pointerLockedDoc == this);
  }
#endif

  PresShell* presShell = GetPresShell();
  if (!presShell) {
    NS_WARNING("SetPointerLock(): No PresShell");
    if (!aElement) {
      // If we are unlocking pointer lock, but for some reason the doc
      // has already detached from the presshell, just ask the event
      // state manager to release the pointer.
      EventStateManager::SetPointerLock(nullptr, nullptr);
      return true;
    }
    return false;
  }
  nsPresContext* presContext = presShell->GetPresContext();
  if (!presContext) {
    NS_WARNING("SetPointerLock(): Unable to get PresContext");
    return false;
  }

  nsCOMPtr<nsIWidget> widget;
  nsIFrame* rootFrame = presShell->GetRootFrame();
  if (!NS_WARN_IF(!rootFrame)) {
    widget = rootFrame->GetNearestWidget();
    NS_WARNING_ASSERTION(widget,
                         "SetPointerLock(): Unable to find widget in "
                         "presShell->GetRootFrame()->GetNearestWidget();");
    if (aElement && !widget) {
      return false;
    }
  }

  // Hide the cursor and set pointer lock for future mouse events
  RefPtr<EventStateManager> esm = presContext->EventStateManager();
  esm->SetCursor(aCursorStyle, nullptr, Nothing(), widget, true);
  EventStateManager::SetPointerLock(widget, aElement);

  return true;
}

void Document::UnlockPointer(Document* aDoc) {
  if (!EventStateManager::sIsPointerLocked) {
    return;
  }

  nsCOMPtr<Document> pointerLockedDoc =
      do_QueryReferent(EventStateManager::sPointerLockedDoc);
  if (!pointerLockedDoc || (aDoc && aDoc != pointerLockedDoc)) {
    return;
  }
  if (!pointerLockedDoc->SetPointerLock(nullptr, StyleCursorKind::Auto)) {
    return;
  }

  nsCOMPtr<Element> pointerLockedElement =
      do_QueryReferent(EventStateManager::sPointerLockedElement);
  ChangePointerLockedElement(nullptr, pointerLockedDoc, pointerLockedElement);

  RefPtr<AsyncEventDispatcher> asyncDispatcher = new AsyncEventDispatcher(
      pointerLockedElement, NS_LITERAL_STRING("MozDOMPointerLock:Exited"),
      CanBubble::eYes, ChromeOnlyDispatch::eYes);
  asyncDispatcher->RunDOMEventWhenSafe();
}

void Document::UpdateVisibilityState() {
  dom::VisibilityState oldState = mVisibilityState;
  mVisibilityState = ComputeVisibilityState();
  if (oldState != mVisibilityState) {
    nsContentUtils::DispatchTrustedEvent(this, ToSupports(this),
                                         NS_LITERAL_STRING("visibilitychange"),
                                         CanBubble::eYes, Cancelable::eNo);
    EnumerateActivityObservers(NotifyActivityChanged, nullptr);
  }

  if (mVisibilityState == dom::VisibilityState::Visible) {
    MaybeActiveMediaComponents();
  }
}

VisibilityState Document::ComputeVisibilityState() const {
  // We have to check a few pieces of information here:
  // 1)  Are we in bfcache (!IsVisible())?  If so, nothing else matters.
  // 2)  Do we have an outer window?  If not, we're hidden.  Note that we don't
  //     want to use GetWindow here because it does weird groveling for windows
  //     in some cases.
  // 3)  Is our outer window background?  If so, we're hidden.
  // Otherwise, we're visible.
  if (!IsVisible() || !mWindow || !mWindow->GetOuterWindow() ||
      mWindow->GetOuterWindow()->IsBackground()) {
    return dom::VisibilityState::Hidden;
  }

  return dom::VisibilityState::Visible;
}

void Document::PostVisibilityUpdateEvent() {
  nsCOMPtr<nsIRunnable> event =
      NewRunnableMethod("Document::UpdateVisibilityState", this,
                        &Document::UpdateVisibilityState);
  Dispatch(TaskCategory::Other, event.forget());
}

void Document::MaybeActiveMediaComponents() {
  if (!mWindow) {
    return;
  }

  GetWindow()->MaybeActiveMediaComponents();
}

void Document::DocAddSizeOfExcludingThis(nsWindowSizes& aWindowSizes) const {
  nsINode::AddSizeOfExcludingThis(aWindowSizes, &aWindowSizes.mDOMOtherSize);

  for (nsIContent* kid = GetFirstChild(); kid; kid = kid->GetNextSibling()) {
    AddSizeOfNodeTree(*kid, aWindowSizes);
  }

  // IMPORTANT: for our ComputedValues measurements, we want to measure
  // ComputedValues accessible from DOM elements before ComputedValues not
  // accessible from DOM elements (i.e. accessible only from the frame tree).
  //
  // Therefore, the measurement of the Document superclass must happen after
  // the measurement of DOM nodes (above), because Document contains the
  // PresShell, which contains the frame tree.
  if (mPresShell) {
    mPresShell->AddSizeOfIncludingThis(aWindowSizes);
  }

  mStyleSet->AddSizeOfIncludingThis(aWindowSizes);

  aWindowSizes.mDOMOtherSize += mLangGroupFontPrefs.SizeOfExcludingThis(
      aWindowSizes.mState.mMallocSizeOf);

  aWindowSizes.mPropertyTablesSize +=
      mPropertyTable.SizeOfExcludingThis(aWindowSizes.mState.mMallocSizeOf);

  if (EventListenerManager* elm = GetExistingListenerManager()) {
    aWindowSizes.mDOMEventListenersCount += elm->ListenerCount();
  }

  if (mNodeInfoManager) {
    mNodeInfoManager->AddSizeOfIncludingThis(aWindowSizes);
  }

  aWindowSizes.mDOMMediaQueryLists += mDOMMediaQueryLists.sizeOfExcludingThis(
      aWindowSizes.mState.mMallocSizeOf);

  for (const MediaQueryList* mql : mDOMMediaQueryLists) {
    aWindowSizes.mDOMMediaQueryLists +=
        mql->SizeOfExcludingThis(aWindowSizes.mState.mMallocSizeOf);
  }

  mContentBlockingLog.AddSizeOfExcludingThis(aWindowSizes);

  DocumentOrShadowRoot::AddSizeOfExcludingThis(aWindowSizes);

  for (auto& sheetArray : mAdditionalSheets) {
    AddSizeOfOwnedSheetArrayExcludingThis(aWindowSizes, sheetArray);
  }
  // Lumping in the loader with the style-sheets size is not ideal,
  // but most of the things in there are in fact stylesheets, so it
  // doesn't seem worthwhile to separate it out.
  aWindowSizes.mLayoutStyleSheetsSize +=
      CSSLoader()->SizeOfIncludingThis(aWindowSizes.mState.mMallocSizeOf);

  aWindowSizes.mDOMOtherSize += mAttrStyleSheet
                                    ? mAttrStyleSheet->DOMSizeOfIncludingThis(
                                          aWindowSizes.mState.mMallocSizeOf)
                                    : 0;

  aWindowSizes.mDOMOtherSize += mStyledLinks.ShallowSizeOfExcludingThis(
      aWindowSizes.mState.mMallocSizeOf);

  // Measurement of the following members may be added later if DMD finds it
  // is worthwhile:
  // - many!
}

void Document::DocAddSizeOfIncludingThis(nsWindowSizes& aWindowSizes) const {
  aWindowSizes.mDOMOtherSize += aWindowSizes.mState.mMallocSizeOf(this);
  DocAddSizeOfExcludingThis(aWindowSizes);
}

void Document::AddSizeOfExcludingThis(nsWindowSizes& aSizes,
                                      size_t* aNodeSize) const {
  // This AddSizeOfExcludingThis() overrides the one from nsINode.  But
  // nsDocuments can only appear at the top of the DOM tree, and we use the
  // specialized DocAddSizeOfExcludingThis() in that case.  So this should never
  // be called.
  MOZ_CRASH();
}

/* static */
void Document::AddSizeOfNodeTree(nsINode& aNode, nsWindowSizes& aWindowSizes) {
  size_t nodeSize = 0;
  aNode.AddSizeOfIncludingThis(aWindowSizes, &nodeSize);

  // This is where we transfer the nodeSize obtained from
  // nsINode::AddSizeOfIncludingThis() to a value in nsWindowSizes.
  switch (aNode.NodeType()) {
    case nsINode::ELEMENT_NODE:
      aWindowSizes.mDOMElementNodesSize += nodeSize;
      break;
    case nsINode::TEXT_NODE:
      aWindowSizes.mDOMTextNodesSize += nodeSize;
      break;
    case nsINode::CDATA_SECTION_NODE:
      aWindowSizes.mDOMCDATANodesSize += nodeSize;
      break;
    case nsINode::COMMENT_NODE:
      aWindowSizes.mDOMCommentNodesSize += nodeSize;
      break;
    default:
      aWindowSizes.mDOMOtherSize += nodeSize;
      break;
  }

  if (EventListenerManager* elm = aNode.GetExistingListenerManager()) {
    aWindowSizes.mDOMEventListenersCount += elm->ListenerCount();
  }

  if (aNode.IsContent()) {
    nsTArray<nsIContent*> anonKids;
    nsContentUtils::AppendNativeAnonymousChildren(aNode.AsContent(), anonKids,
                                                  nsIContent::eAllChildren);
    for (nsIContent* anonKid : anonKids) {
      AddSizeOfNodeTree(*anonKid, aWindowSizes);
    }

    if (auto* element = Element::FromNode(aNode)) {
      if (ShadowRoot* shadow = element->GetShadowRoot()) {
        AddSizeOfNodeTree(*shadow, aWindowSizes);
      }

      for (nsXBLBinding* binding = element->GetXBLBinding(); binding;
           binding = binding->GetBaseBinding()) {
        if (nsIContent* anonContent = binding->GetAnonymousContent()) {
          AddSizeOfNodeTree(*anonContent, aWindowSizes);
        }
      }
    }
  }

  // NOTE(emilio): If you feel smart and want to change this function to use
  // GetNextNode(), think twice, since you'd need to handle <xbl:content> in a
  // sane way, and kids of <content> won't point to the parent, so we'd never
  // find the root node where we should stop at.
  for (nsIContent* kid = aNode.GetFirstChild(); kid;
       kid = kid->GetNextSibling()) {
    AddSizeOfNodeTree(*kid, aWindowSizes);
  }
}

already_AddRefed<Document> Document::Constructor(const GlobalObject& aGlobal,
                                                 ErrorResult& rv) {
  nsCOMPtr<nsIScriptGlobalObject> global =
      do_QueryInterface(aGlobal.GetAsSupports());
  if (!global) {
    rv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  nsCOMPtr<nsIScriptObjectPrincipal> prin =
      do_QueryInterface(aGlobal.GetAsSupports());
  if (!prin) {
    rv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  nsCOMPtr<nsIURI> uri;
  NS_NewURI(getter_AddRefs(uri), "about:blank");
  if (!uri) {
    rv.Throw(NS_ERROR_OUT_OF_MEMORY);
    return nullptr;
  }

  nsCOMPtr<Document> doc;
  nsresult res = NS_NewDOMDocument(
      getter_AddRefs(doc), VoidString(), EmptyString(), nullptr, uri, uri,
      prin->GetPrincipal(), true, global, DocumentFlavorPlain);
  if (NS_FAILED(res)) {
    rv.Throw(res);
    return nullptr;
  }

  doc->SetReadyStateInternal(Document::READYSTATE_COMPLETE);

  return doc.forget();
}

XPathExpression* Document::CreateExpression(const nsAString& aExpression,
                                            XPathNSResolver* aResolver,
                                            ErrorResult& rv) {
  return XPathEvaluator()->CreateExpression(aExpression, aResolver, rv);
}

nsINode* Document::CreateNSResolver(nsINode& aNodeResolver) {
  return XPathEvaluator()->CreateNSResolver(aNodeResolver);
}

already_AddRefed<XPathResult> Document::Evaluate(
    JSContext* aCx, const nsAString& aExpression, nsINode& aContextNode,
    XPathNSResolver* aResolver, uint16_t aType, JS::Handle<JSObject*> aResult,
    ErrorResult& rv) {
  return XPathEvaluator()->Evaluate(aCx, aExpression, aContextNode, aResolver,
                                    aType, aResult, rv);
}

already_AddRefed<nsIXULWindow> Document::GetXULWindowIfToplevelChrome() const {
  nsCOMPtr<nsIDocShellTreeItem> item = GetDocShell();
  if (!item) {
    return nullptr;
  }
  nsCOMPtr<nsIDocShellTreeOwner> owner;
  item->GetTreeOwner(getter_AddRefs(owner));
  nsCOMPtr<nsIXULWindow> xulWin = do_GetInterface(owner);
  if (!xulWin) {
    return nullptr;
  }
  nsCOMPtr<nsIDocShell> xulWinShell;
  xulWin->GetDocShell(getter_AddRefs(xulWinShell));
  if (!SameCOMIdentity(xulWinShell, item)) {
    return nullptr;
  }
  return xulWin.forget();
}

Document* Document::GetTopLevelContentDocument() {
  Document* parent;

  if (!mLoadedAsData) {
    parent = this;
  } else {
    nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(GetScopeObject());
    if (!window) {
      return nullptr;
    }

    parent = window->GetExtantDoc();
    if (!parent) {
      return nullptr;
    }
  }

  do {
    if (parent->IsTopLevelContentDocument()) {
      break;
    }

    // If we ever have a non-content parent before we hit a toplevel content
    // parent, then we're never going to find one.  Just bail.
    if (!parent->IsContentDocument()) {
      return nullptr;
    }

    parent = parent->GetParentDocument();
  } while (parent);

  return parent;
}

static bool MightBeChromeScheme(nsIURI* aURI) {
  MOZ_ASSERT(aURI);
  bool isChrome = true;
  aURI->SchemeIs("chrome", &isChrome);
  return isChrome;
}

static bool MightBeAboutOrChromeScheme(nsIURI* aURI) {
  MOZ_ASSERT(aURI);
  bool isAbout = true;
  aURI->SchemeIs("about", &isAbout);
  return isAbout || MightBeChromeScheme(aURI);
}

void Document::PropagateUseCounters(Document* aParentDocument) {
  MOZ_ASSERT(this != aParentDocument);

  // Don't count chrome resources, even in the web content.
  nsCOMPtr<nsIURI> uri;
  NodePrincipal()->GetURI(getter_AddRefs(uri));
  if (!uri || MightBeChromeScheme(uri)) {
    return;
  }

  // What really matters here is that our use counters get propagated as
  // high up in the content document hierarchy as possible.  So,
  // starting with aParentDocument, we need to find the toplevel content
  // document, and propagate our use counters into its
  // mChildDocumentUseCounters.
  Document* contentParent = aParentDocument->GetTopLevelContentDocument();

  if (!contentParent) {
    return;
  }

  contentParent->mChildDocumentUseCounters |= mUseCounters;
  contentParent->mChildDocumentUseCounters |= mChildDocumentUseCounters;
}

void Document::SetPageUseCounter(UseCounter aUseCounter) {
  // We want to set the use counter on the "page" that owns us; the definition
  // of "page" depends on what kind of document we are.  See the comments below
  // for details.  In any event, checking all the conditions below is
  // reasonably expensive, so we cache whether we've notified our owning page.
  if (mNotifiedPageForUseCounter[aUseCounter]) {
    return;
  }
  mNotifiedPageForUseCounter[aUseCounter] = true;

  if (mDisplayDocument) {
    // If we are a resource document, we won't have a docshell and so we won't
    // record any page use counters on this document.  Instead, we should
    // forward it up to the document that loaded us.
    MOZ_ASSERT(!mDocumentContainer);
    mDisplayDocument->SetChildDocumentUseCounter(aUseCounter);
    return;
  }

  if (IsBeingUsedAsImage()) {
    // If this is an SVG image document, we also won't have a docshell.
    MOZ_ASSERT(!mDocumentContainer);
    return;
  }

  // We only care about use counters in content.  If we're already a toplevel
  // content document, then we should have already set the use counter on
  // ourselves, and we are done.
  Document* contentParent = GetTopLevelContentDocument();
  if (!contentParent) {
    return;
  }

  if (this == contentParent) {
    MOZ_ASSERT(GetUseCounter(aUseCounter));
    return;
  }

  contentParent->SetChildDocumentUseCounter(aUseCounter);
}

bool Document::HasScriptsBlockedBySandbox() {
  return mSandboxFlags & SANDBOXED_SCRIPTS;
}

bool Document::InlineScriptAllowedByCSP() {
  // this function assumes the inline script is parser created
  //  (e.g., before setting attribute(!) event handlers)
  nsCOMPtr<nsIContentSecurityPolicy> csp;
  nsresult rv = NodePrincipal()->GetCsp(getter_AddRefs(csp));
  NS_ENSURE_SUCCESS(rv, true);
  bool allowsInlineScript = true;
  if (csp) {
    nsresult rv = csp->GetAllowsInline(
        nsIContentPolicy::TYPE_SCRIPT,
        EmptyString(),  // aNonce
        true,           // aParserCreated
        nullptr,        // aTriggeringElement
        nullptr,        // aCSPEventListener
        EmptyString(),  // FIXME get script sample (bug 1314567)
        0,              // aLineNumber
        0,              // aColumnNumber
        &allowsInlineScript);
    NS_ENSURE_SUCCESS(rv, true);
  }
  return allowsInlineScript;
}

static bool ReportExternalResourceUseCounters(Document* aDocument,
                                              void* aData) {
  const auto reportKind =
      Document::UseCounterReportKind::eIncludeExternalResources;
  aDocument->ReportUseCounters(reportKind);
  return true;
}

void Document::ReportUseCounters(UseCounterReportKind aKind) {
  static const bool sDebugUseCounters = false;
  if (mReportedUseCounters) {
    return;
  }

  mReportedUseCounters = true;

  if (aKind == UseCounterReportKind::eIncludeExternalResources) {
    EnumerateExternalResources(ReportExternalResourceUseCounters, nullptr);
  }

  if (Telemetry::HistogramUseCounterCount > 0 &&
      (IsContentDocument() || IsResourceDoc())) {
    nsCOMPtr<nsIURI> uri;
    NodePrincipal()->GetURI(getter_AddRefs(uri));
    if (!uri || MightBeAboutOrChromeScheme(uri)) {
      return;
    }

    if (sDebugUseCounters) {
      nsCString spec = uri->GetSpecOrDefault();

      // URIs can be rather long for data documents, so truncate them to
      // some reasonable length.
      spec.Truncate(std::min(128U, spec.Length()));
      printf("-- Use counters for %s --\n", spec.get());
    }

    // We keep separate counts for individual documents and top-level
    // pages to more accurately track how many web pages might break if
    // certain features were removed.  Consider the case of a single
    // HTML document with several SVG images and/or iframes with
    // sub-documents of their own.  If we maintained a single set of use
    // counters and all the sub-documents use a particular feature, then
    // telemetry would indicate that we would be breaking N documents if
    // that feature were removed.  Whereas with a document/top-level
    // page split, we can see that N documents would be affected, but
    // only a single web page would be affected.

    // The difference between the values of these two histograms and the
    // related use counters below tell us how many pages did *not* use
    // the feature in question.  For instance, if we see that a given
    // session has destroyed 30 content documents, but a particular use
    // counter shows only a count of 5, we can infer that the use
    // counter was *not* used in 25 of those 30 documents.
    //
    // We do things this way, rather than accumulating a boolean flag
    // for each use counter, to avoid sending histograms for features
    // that don't get widely used.  Doing things in this fashion means
    // smaller telemetry payloads and faster processing on the server
    // side.
    Telemetry::Accumulate(Telemetry::CONTENT_DOCUMENTS_DESTROYED, 1);
    if (IsTopLevelContentDocument()) {
      Telemetry::Accumulate(Telemetry::TOP_LEVEL_CONTENT_DOCUMENTS_DESTROYED,
                            1);
    }

    for (int32_t c = 0; c < eUseCounter_Count; ++c) {
      UseCounter uc = static_cast<UseCounter>(c);

      Telemetry::HistogramID id = static_cast<Telemetry::HistogramID>(
          Telemetry::HistogramFirstUseCounter + uc * 2);
      bool value = GetUseCounter(uc);

      if (value) {
        if (sDebugUseCounters) {
          const char* name = Telemetry::GetHistogramName(id);
          if (name) {
            printf("  %s", name);
          } else {
            printf("  #%d", id);
          }
          printf(": %d\n", value);
        }

        Telemetry::Accumulate(id, 1);
      }

      if (IsTopLevelContentDocument()) {
        id = static_cast<Telemetry::HistogramID>(
            Telemetry::HistogramFirstUseCounter + uc * 2 + 1);
        value = GetUseCounter(uc) || GetChildDocumentUseCounter(uc);

        if (value) {
          if (sDebugUseCounters) {
            const char* name = Telemetry::GetHistogramName(id);
            if (name) {
              printf("  %s", name);
            } else {
              printf("  #%d", id);
            }
            printf(": %d\n", value);
          }

          Telemetry::Accumulate(id, 1);
        }
      }
    }
  }

  if (IsTopLevelContentDocument()) {
    CSSIntCoord adjustmentLength =
        CSSPixel::FromAppUnits(mScrollAnchorAdjustmentLength).Rounded();
    Telemetry::Accumulate(Telemetry::SCROLL_ANCHOR_ADJUSTMENT_LENGTH,
                          adjustmentLength);
    Telemetry::Accumulate(Telemetry::SCROLL_ANCHOR_ADJUSTMENT_COUNT,
                          mScrollAnchorAdjustmentCount);
  }
}

void Document::UpdateIntersectionObservations() {
  if (mIntersectionObservers.IsEmpty()) {
    return;
  }

  DOMHighResTimeStamp time = 0;
  if (nsPIDOMWindowInner* window = GetInnerWindow()) {
    Performance* perf = window->GetPerformance();
    if (perf) {
      time = perf->Now();
    }
  }
  nsTArray<RefPtr<DOMIntersectionObserver>> observers(
      mIntersectionObservers.Count());
  for (auto iter = mIntersectionObservers.Iter(); !iter.Done(); iter.Next()) {
    DOMIntersectionObserver* observer = iter.Get()->GetKey();
    observers.AppendElement(observer);
  }
  for (const auto& observer : observers) {
    if (observer) {
      observer->Update(this, time);
    }
  }
}

void Document::ScheduleIntersectionObserverNotification() {
  if (mIntersectionObservers.IsEmpty()) {
    return;
  }
  MOZ_RELEASE_ASSERT(NS_IsMainThread());
  nsCOMPtr<nsIRunnable> notification =
      NewRunnableMethod("Document::NotifyIntersectionObservers", this,
                        &Document::NotifyIntersectionObservers);
  Dispatch(TaskCategory::Other, notification.forget());
}

void Document::NotifyIntersectionObservers() {
  nsTArray<RefPtr<DOMIntersectionObserver>> observers(
      mIntersectionObservers.Count());
  for (auto iter = mIntersectionObservers.Iter(); !iter.Done(); iter.Next()) {
    DOMIntersectionObserver* observer = iter.Get()->GetKey();
    observers.AppendElement(observer);
  }
  for (const auto& observer : observers) {
    if (observer) {
      observer->Notify();
    }
  }
}

static bool NotifyLayerManagerRecreatedCallback(Document* aDocument,
                                                void* aData) {
  aDocument->NotifyLayerManagerRecreated();
  return true;
}

void Document::NotifyLayerManagerRecreated() {
  EnumerateActivityObservers(NotifyActivityChanged, nullptr);
  EnumerateSubDocuments(NotifyLayerManagerRecreatedCallback, nullptr);
}

XPathEvaluator* Document::XPathEvaluator() {
  if (!mXPathEvaluator) {
    mXPathEvaluator.reset(new dom::XPathEvaluator(this));
  }
  return mXPathEvaluator.get();
}

already_AddRefed<nsIDocumentEncoder> Document::GetCachedEncoder() {
  return mCachedEncoder.forget();
}

void Document::SetCachedEncoder(already_AddRefed<nsIDocumentEncoder> aEncoder) {
  mCachedEncoder = aEncoder;
}

void Document::SetContentTypeInternal(const nsACString& aType) {
  if (!IsHTMLOrXHTML() && mDefaultElementType == kNameSpaceID_None &&
      aType.EqualsLiteral("application/xhtml+xml")) {
    mDefaultElementType = kNameSpaceID_XHTML;
  }

  mCachedEncoder = nullptr;
  mContentType = aType;
  mContentTypeForWriteCalls = aType;
}

nsILoadContext* Document::GetLoadContext() const { return mDocumentContainer; }

nsIDocShell* Document::GetDocShell() const { return mDocumentContainer; }

void Document::SetStateObject(nsIStructuredCloneContainer* scContainer) {
  mStateObjectContainer = scContainer;
  mStateObjectCached = nullptr;
}

Document::DocumentTheme Document::GetDocumentLWTheme() {
  if (mDocLWTheme == Doc_Theme_Uninitialized) {
    mDocLWTheme = ThreadSafeGetDocumentLWTheme();
  }
  return mDocLWTheme;
}

Document::DocumentTheme Document::ThreadSafeGetDocumentLWTheme() const {
  if (!nsContentUtils::IsSystemPrincipal(NodePrincipal())) {
    return Doc_Theme_None;
  }

  if (mDocLWTheme != Doc_Theme_Uninitialized) {
    return mDocLWTheme;
  }

  DocumentTheme theme = Doc_Theme_None;  // No lightweight theme by default
  Element* element = GetRootElement();
  if (element && element->AttrValueIs(kNameSpaceID_None, nsGkAtoms::lwtheme,
                                      nsGkAtoms::_true, eCaseMatters)) {
    theme = Doc_Theme_Neutral;
    nsAutoString lwTheme;
    element->GetAttr(kNameSpaceID_None, nsGkAtoms::lwthemetextcolor, lwTheme);
    if (lwTheme.EqualsLiteral("dark")) {
      theme = Doc_Theme_Dark;
    } else if (lwTheme.EqualsLiteral("bright")) {
      theme = Doc_Theme_Bright;
    }
  }

  return theme;
}

already_AddRefed<Element> Document::CreateHTMLElement(nsAtom* aTag) {
  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
  nodeInfo = mNodeInfoManager->GetNodeInfo(aTag, nullptr, kNameSpaceID_XHTML,
                                           ELEMENT_NODE);
  MOZ_ASSERT(nodeInfo, "GetNodeInfo should never fail");

  nsCOMPtr<Element> element;
  DebugOnly<nsresult> rv =
      NS_NewHTMLElement(getter_AddRefs(element), nodeInfo.forget(),
                        mozilla::dom::NOT_FROM_PARSER);

  MOZ_ASSERT(NS_SUCCEEDED(rv), "NS_NewHTMLElement should never fail");
  return element.forget();
}

bool MarkDocumentTreeToBeInSyncOperation(Document* aDoc, void* aData) {
  auto* documents = static_cast<nsTArray<nsCOMPtr<Document>>*>(aData);
  if (aDoc) {
    aDoc->SetIsInSyncOperation(true);
    if (nsCOMPtr<nsPIDOMWindowInner> window = aDoc->GetInnerWindow()) {
      window->TimeoutManager().BeginSyncOperation();
    }
    documents->AppendElement(aDoc);
    aDoc->EnumerateSubDocuments(MarkDocumentTreeToBeInSyncOperation, aData);
  }
  return true;
}

nsAutoSyncOperation::nsAutoSyncOperation(Document* aDoc) {
  mMicroTaskLevel = 0;
  CycleCollectedJSContext* ccjs = CycleCollectedJSContext::Get();
  if (ccjs) {
    mMicroTaskLevel = ccjs->MicroTaskLevel();
    ccjs->SetMicroTaskLevel(0);
  }
  if (aDoc) {
    if (nsPIDOMWindowOuter* win = aDoc->GetWindow()) {
      if (nsCOMPtr<nsPIDOMWindowOuter> top = win->GetTop()) {
        nsCOMPtr<Document> doc = top->GetExtantDoc();
        MarkDocumentTreeToBeInSyncOperation(doc, &mDocuments);
      }
    }
  }
}

nsAutoSyncOperation::~nsAutoSyncOperation() {
  for (RefPtr<Document>& doc : mDocuments) {
    if (nsCOMPtr<nsPIDOMWindowInner> window = doc->GetInnerWindow()) {
      window->TimeoutManager().EndSyncOperation();
    }
    doc->SetIsInSyncOperation(false);
  }
  CycleCollectedJSContext* ccjs = CycleCollectedJSContext::Get();
  if (ccjs) {
    ccjs->SetMicroTaskLevel(mMicroTaskLevel);
  }
}

gfxUserFontSet* Document::GetUserFontSet() {
  if (!mFontFaceSet) {
    return nullptr;
  }

  return mFontFaceSet->GetUserFontSet();
}

void Document::FlushUserFontSet() {
  if (!mFontFaceSetDirty) {
    return;
  }

  mFontFaceSetDirty = false;

  if (gfxPlatform::GetPlatform()->DownloadableFontsEnabled()) {
    nsTArray<nsFontFaceRuleContainer> rules;
    RefPtr<PresShell> presShell = GetPresShell();
    if (presShell) {
      MOZ_ASSERT(mStyleSetFilled);
      mStyleSet->AppendFontFaceRules(rules);
    }

    if (!mFontFaceSet && !rules.IsEmpty()) {
      nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(GetScopeObject());
      mFontFaceSet = new FontFaceSet(window, this);
    }

    bool changed = false;
    if (mFontFaceSet) {
      changed = mFontFaceSet->UpdateRules(rules);
    }

    // We need to enqueue a style change reflow (for later) to
    // reflect that we're modifying @font-face rules.  (However,
    // without a reflow, nothing will happen to start any downloads
    // that are needed.)
    if (changed && presShell) {
      if (nsPresContext* presContext = presShell->GetPresContext()) {
        presContext->UserFontSetUpdated();
      }
    }
  }
}

void Document::MarkUserFontSetDirty() {
  if (mFontFaceSetDirty) {
    return;
  }
  mFontFaceSetDirty = true;
  if (PresShell* presShell = GetPresShell()) {
    presShell->EnsureStyleFlush();
  }
}

FontFaceSet* Document::Fonts() {
  if (!mFontFaceSet) {
    nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(GetScopeObject());
    mFontFaceSet = new FontFaceSet(window, this);
    FlushUserFontSet();
  }
  return mFontFaceSet;
}

void Document::ReportHasScrollLinkedEffect() {
  if (mHasScrollLinkedEffect) {
    // We already did this once for this document, don't do it again.
    return;
  }
  mHasScrollLinkedEffect = true;
  nsContentUtils::ReportToConsole(
      nsIScriptError::warningFlag, NS_LITERAL_CSTRING("Async Pan/Zoom"), this,
      nsContentUtils::eLAYOUT_PROPERTIES, "ScrollLinkedEffectFound2");
}

void Document::SetUserHasInteracted() {
  MOZ_LOG(gUserInteractionPRLog, LogLevel::Debug,
          ("Document %p has been interacted by user.", this));

  // We maybe need to update the user-interaction permission.
  MaybeStoreUserInteractionAsPermission();

  if (mUserHasInteracted) {
    return;
  }

  mUserHasInteracted = true;

  if (mChannel) {
    nsCOMPtr<nsILoadInfo> loadInfo = mChannel->LoadInfo();
    loadInfo->SetDocumentHasUserInteracted(true);
  }

  MaybeAllowStorageForOpenerAfterUserInteraction();
}

BrowsingContext* Document::GetBrowsingContext() const {
  nsPIDOMWindowOuter* outer = GetWindow();
  return outer ? outer->GetBrowsingContext() : nullptr;
}

void Document::NotifyUserGestureActivation() {
  if (HasBeenUserGestureActivated()) {
    return;
  }

  RefPtr<BrowsingContext> bc = GetBrowsingContext();
  if (!bc) {
    return;
  }
  bc->NotifyUserGestureActivation();
}

bool Document::HasBeenUserGestureActivated() {
  RefPtr<BrowsingContext> bc = GetBrowsingContext();
  if (!bc) {
    return false;
  }
  return bc->GetUserGestureActivation();
}

void Document::MaybeNotifyAutoplayBlocked() {
  Document* topLevelDoc = GetTopLevelContentDocument();
  if (!topLevelDoc) {
    return;
  }

  // This event is used to notify front-end side that we've blocked autoplay,
  // so front-end side should show blocking icon as well.
  RefPtr<AsyncEventDispatcher> asyncDispatcher = new AsyncEventDispatcher(
      topLevelDoc, NS_LITERAL_STRING("GloballyAutoplayBlocked"),
      CanBubble::eYes, ChromeOnlyDispatch::eYes);
  asyncDispatcher->PostDOMEvent();
}

void Document::ClearUserGestureActivation() {
  if (!HasBeenUserGestureActivated()) {
    return;
  }
  RefPtr<BrowsingContext> bc = GetBrowsingContext();
  if (!bc) {
    return;
  }
  bc->NotifyResetUserGestureActivation();
}

void Document::SetDocTreeHadAudibleMedia() {
  Document* topLevelDoc = GetTopLevelContentDocument();
  if (!topLevelDoc) {
    return;
  }

  topLevelDoc->mDocTreeHadAudibleMedia = true;
}

void Document::SetDocTreeHadPlayRevoked() {
  Document* topLevelDoc = GetTopLevelContentDocument();
  if (topLevelDoc) {
    topLevelDoc->mDocTreeHadPlayRevoked = true;
  }
}

DocumentAutoplayPolicy Document::AutoplayPolicy() const {
  return AutoplayPolicy::IsAllowedToPlay(*this);
}

void Document::MaybeAllowStorageForOpenerAfterUserInteraction() {
  if (CookieSettings()->GetCookieBehavior() !=
      nsICookieService::BEHAVIOR_REJECT_TRACKER) {
    return;
  }

  // This will probably change for project fission, but currently this document
  // and the opener are on the same process. In the future, we should make this
  // part async.

  nsPIDOMWindowInner* inner = GetInnerWindow();
  if (NS_WARN_IF(!inner)) {
    return;
  }

  nsCOMPtr<nsPIDOMWindowOuter> outer = inner->GetOuterWindow();
  if (NS_WARN_IF(!outer)) {
    return;
  }

  nsCOMPtr<nsPIDOMWindowOuter> outerOpener = outer->GetOpener();
  if (!outerOpener) {
    return;
  }

  nsPIDOMWindowInner* openerInner = outerOpener->GetCurrentInnerWindow();
  if (NS_WARN_IF(!openerInner)) {
    return;
  }

  // Let's take the principal from the opener.
  Document* openerDocument = openerInner->GetExtantDoc();
  if (NS_WARN_IF(!openerDocument)) {
    return;
  }

  nsCOMPtr<nsIURI> openerURI = openerDocument->GetDocumentURI();
  if (NS_WARN_IF(!openerURI)) {
    return;
  }

  // No tracking resource.
  if (!nsContentUtils::IsTrackingResourceWindow(inner)) {
    return;
  }

  // If the opener is not a 3rd party and if this window is not a 3rd party, we
  // should not continue.
  if (!nsContentUtils::IsThirdPartyWindowOrChannel(inner, nullptr, openerURI) &&
      !nsContentUtils::IsThirdPartyWindowOrChannel(openerInner, nullptr,
                                                   nullptr)) {
    return;
  }

  // We don't care when the asynchronous work finishes here.
  Unused << AntiTrackingCommon::AddFirstPartyStorageAccessGrantedFor(
      NodePrincipal(), openerInner,
      AntiTrackingCommon::eOpenerAfterUserInteraction);
}

namespace {

// Documents can stay alive for days. We don't want to update the permission
// value at any user-interaction, and, using a timer triggered any X seconds
// should be good enough. 'X' is taken from
// privacy.userInteraction.document.interval pref.
//  We also want to store the user-interaction before shutting down, and, for
//  this reason, this class implements nsIAsyncShutdownBlocker interface.
class UserIntractionTimer final : public Runnable,
                                  public nsITimerCallback,
                                  public nsIAsyncShutdownBlocker {
 public:
  NS_DECL_ISUPPORTS_INHERITED

  explicit UserIntractionTimer(Document* aDocument)
      : Runnable("UserIntractionTimer"),
        mPrincipal(aDocument->NodePrincipal()),
        mDocument(do_GetWeakReference(aDocument)) {
    static int32_t userInteractionTimerId = 0;
    // Blocker names must be unique. Let's create it now because when needed,
    // the document could be already gone.
    mBlockerName.AppendPrintf("UserInteractionTimer %d for document %p",
                              ++userInteractionTimerId, aDocument);
  }

  // Runnable interface

  NS_IMETHOD
  Run() override {
    uint32_t interval =
        StaticPrefs::privacy_userInteraction_document_interval();
    if (!interval) {
      return NS_OK;
    }

    RefPtr<UserIntractionTimer> self = this;
    auto raii =
        MakeScopeExit([self] { self->CancelTimerAndStoreUserInteraction(); });

    nsresult rv = NS_NewTimerWithCallback(
        getter_AddRefs(mTimer), this, interval * 1000, nsITimer::TYPE_ONE_SHOT,
        SystemGroup::EventTargetFor(TaskCategory::Other));
    NS_ENSURE_SUCCESS(rv, NS_OK);

    nsCOMPtr<nsIAsyncShutdownClient> phase = GetShutdownPhase();
    NS_ENSURE_TRUE(!!phase, NS_OK);

    rv = phase->AddBlocker(this, NS_LITERAL_STRING(__FILE__), __LINE__,
                           NS_LITERAL_STRING("UserIntractionTimer shutdown"));
    NS_ENSURE_SUCCESS(rv, NS_OK);

    raii.release();
    return NS_OK;
  }

  // nsITimerCallback interface

  NS_IMETHOD
  Notify(nsITimer* aTimer) override {
    StoreUserInteraction();
    return NS_OK;
  }

#ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY
  using nsINamed::GetName;
#endif

  // nsIAsyncShutdownBlocker interface

  NS_IMETHOD
  GetName(nsAString& aName) override {
    aName = mBlockerName;
    return NS_OK;
  }

  NS_IMETHOD
  BlockShutdown(nsIAsyncShutdownClient* aClient) override {
    CancelTimerAndStoreUserInteraction();
    return NS_OK;
  }

  NS_IMETHOD
  GetState(nsIPropertyBag**) override { return NS_OK; }

 private:
  ~UserIntractionTimer() = default;

  void StoreUserInteraction() {
    // Remove the shutting down blocker
    nsCOMPtr<nsIAsyncShutdownClient> phase = GetShutdownPhase();
    if (phase) {
      phase->RemoveBlocker(this);
    }

    // If the document is not gone, let's reset its timer flag.
    nsCOMPtr<Document> document = do_QueryReferent(mDocument);
    if (document) {
      AntiTrackingCommon::StoreUserInteractionFor(mPrincipal);
      document->ResetUserInteractionTimer();
    }
  }

  void CancelTimerAndStoreUserInteraction() {
    if (mTimer) {
      mTimer->Cancel();
      mTimer = nullptr;
    }

    StoreUserInteraction();
  }

  static already_AddRefed<nsIAsyncShutdownClient> GetShutdownPhase() {
    nsCOMPtr<nsIAsyncShutdownService> svc = services::GetAsyncShutdown();
    NS_ENSURE_TRUE(!!svc, nullptr);

    nsCOMPtr<nsIAsyncShutdownClient> phase;
    nsresult rv = svc->GetXpcomWillShutdown(getter_AddRefs(phase));
    NS_ENSURE_SUCCESS(rv, nullptr);

    return phase.forget();
  }

  nsCOMPtr<nsIPrincipal> mPrincipal;
  nsWeakPtr mDocument;

  nsCOMPtr<nsITimer> mTimer;

  nsString mBlockerName;
};

NS_IMPL_ISUPPORTS_INHERITED(UserIntractionTimer, Runnable, nsITimerCallback,
                            nsIAsyncShutdownBlocker)

}  // namespace

void Document::MaybeStoreUserInteractionAsPermission() {
  // We care about user-interaction stored only for top-level documents.
  if (GetSameTypeParentDocument()) {
    return;
  }

  if (!mUserHasInteracted) {
    // First interaction, let's store this info now.
    AntiTrackingCommon::StoreUserInteractionFor(NodePrincipal());
    return;
  }

  if (mHasUserInteractionTimerScheduled) {
    return;
  }

  nsCOMPtr<nsIRunnable> task = new UserIntractionTimer(this);
  nsresult rv = NS_DispatchToCurrentThreadQueue(task.forget(), 2500,
                                                EventQueuePriority::Idle);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return;
  }

  // This value will be reset by the timer.
  mHasUserInteractionTimerScheduled = true;
}

void Document::ResetUserInteractionTimer() {
  mHasUserInteractionTimerScheduled = false;
}

bool Document::IsExtensionPage() const {
  return Preferences::GetBool("media.autoplay.allow-extension-background-pages",
                              true) &&
         BasePrincipal::Cast(NodePrincipal())->AddonPolicy();
}

Document* Document::GetSameTypeParentDocument() {
  nsCOMPtr<nsIDocShellTreeItem> current = GetDocShell();
  if (!current) {
    return nullptr;
  }

  nsCOMPtr<nsIDocShellTreeItem> parent;
  current->GetSameTypeParent(getter_AddRefs(parent));
  if (!parent) {
    return nullptr;
  }

  return parent->GetDocument();
}

void Document::TraceProtos(JSTracer* aTrc) {
  if (mPrototypeDocument) {
    mPrototypeDocument->TraceProtos(aTrc);
  }
}

/**
 * Retrieves the classification of the Flash plugins in the document based on
 * the classification lists. For more information, see
 * toolkit/components/url-classifier/flash-block-lists.rst
 */
FlashClassification Document::DocumentFlashClassification() {
  // If neither pref is on, skip the null-principal and principal URI checks.
  if (!StaticPrefs::plugins_http_https_only() &&
      !StaticPrefs::plugins_flashBlock_enabled()) {
    return FlashClassification::Unknown;
  }

  if (NodePrincipal()->GetIsNullPrincipal()) {
    return FlashClassification::Denied;
  }

  nsCOMPtr<nsIURI> classificationURI;
  nsresult rv = NodePrincipal()->GetURI(getter_AddRefs(classificationURI));
  if (NS_FAILED(rv) || !classificationURI) {
    return FlashClassification::Denied;
  }

  if (StaticPrefs::plugins_http_https_only()) {
    // Only allow plugins for documents from an HTTP/HTTPS origin. This should
    // allow dependent data: URIs to load plugins, but not:
    // * chrome documents
    // * "bare" data: loads
    // * FTP/gopher/file
    nsAutoCString scheme;
    rv = classificationURI->GetScheme(scheme);
    if (NS_WARN_IF(NS_FAILED(rv)) ||
        !(scheme.EqualsLiteral("http") || scheme.EqualsLiteral("https"))) {
      return FlashClassification::Denied;
    }
  }

  // If flash blocking is disabled, it is equivalent to all sites being
  // on neither list.
  if (!StaticPrefs::plugins_flashBlock_enabled()) {
    return FlashClassification::Unknown;
  }

  if (mFlashClassification == FlashClassification::Unknown) {
    mFlashClassification = DocumentFlashClassificationInternal();
  }

  return mFlashClassification;
}

void Document::AddResizeObserver(ResizeObserver* aResizeObserver) {
  if (!mResizeObserverController) {
    mResizeObserverController = MakeUnique<ResizeObserverController>(this);
  }

  mResizeObserverController->AddResizeObserver(aResizeObserver);
}

void Document::ScheduleResizeObserversNotification() const {
  if (!mResizeObserverController) {
    return;
  }

  mResizeObserverController->ScheduleNotification();
}

/**
 * Initializes |mIsThirdPartyForFlashClassifier| if necessary and returns its
 * value. The value returned represents whether this document should be
 * considered Third-Party.
 *
 * A top-level document cannot be a considered Third-Party; only subdocuments
 * may. For a subdocument to be considered Third-Party, it must meet ANY ONE
 * of the following requirements:
 *  - The document's parent is Third-Party
 *  - The document has a different scheme (http/https) than its parent document
 *  - The document's domain and subdomain do not match those of its parent
 *    document.
 *
 * If there is an error in determining whether the document is Third-Party,
 * it will be assumed to be Third-Party for security reasons.
 */
bool Document::IsThirdPartyForFlashClassifier() {
  if (mIsThirdPartyForFlashClassifier.isSome()) {
    return mIsThirdPartyForFlashClassifier.value();
  }

  nsCOMPtr<nsIDocShellTreeItem> docshell = this->GetDocShell();
  if (!docshell) {
    mIsThirdPartyForFlashClassifier.emplace(true);
    return mIsThirdPartyForFlashClassifier.value();
  }

  nsCOMPtr<nsIDocShellTreeItem> parent;
  nsresult rv = docshell->GetSameTypeParent(getter_AddRefs(parent));
  MOZ_ASSERT(NS_SUCCEEDED(rv),
             "nsIDocShellTreeItem::GetSameTypeParent should never fail");
  bool isTopLevel = !parent;

  if (isTopLevel) {
    mIsThirdPartyForFlashClassifier.emplace(false);
    return mIsThirdPartyForFlashClassifier.value();
  }

  nsCOMPtr<Document> parentDocument = GetParentDocument();
  if (!parentDocument) {
    // Failure
    mIsThirdPartyForFlashClassifier.emplace(true);
    return mIsThirdPartyForFlashClassifier.value();
  }

  if (parentDocument->IsThirdPartyForFlashClassifier()) {
    mIsThirdPartyForFlashClassifier.emplace(true);
    return mIsThirdPartyForFlashClassifier.value();
  }

  nsCOMPtr<nsIPrincipal> principal = NodePrincipal();
  nsCOMPtr<nsIPrincipal> parentPrincipal = parentDocument->GetPrincipal();

  bool principalsMatch = false;
  rv = principal->Equals(parentPrincipal, &principalsMatch);

  if (NS_WARN_IF(NS_FAILED(rv))) {
    // Failure
    mIsThirdPartyForFlashClassifier.emplace(true);
    return mIsThirdPartyForFlashClassifier.value();
  }

  if (!principalsMatch) {
    mIsThirdPartyForFlashClassifier.emplace(true);
    return mIsThirdPartyForFlashClassifier.value();
  }

  // Fall-through. Document is not a Third-Party Document.
  mIsThirdPartyForFlashClassifier.emplace(false);
  return mIsThirdPartyForFlashClassifier.value();
}

FlashClassification Document::DocumentFlashClassificationInternal() {
  FlashClassification classification = FlashClassification::Unknown;

  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(GetChannel());
  if (httpChannel) {
    nsIHttpChannel::FlashPluginState state = nsIHttpChannel::FlashPluginUnknown;
    httpChannel->GetFlashPluginState(&state);

    // Allow unknown children to inherit allowed status from parent, but do not
    // allow denied children to do so.

    if (state == nsIHttpChannel::FlashPluginDeniedInSubdocuments &&
        IsThirdPartyForFlashClassifier()) {
      return FlashClassification::Denied;
    }

    if (state == nsIHttpChannel::FlashPluginDenied) {
      return FlashClassification::Denied;
    }

    if (state == nsIHttpChannel::FlashPluginAllowed) {
      classification = FlashClassification::Allowed;
    }
  }

  if (IsTopLevelContentDocument()) {
    return classification;
  }

  Document* parentDocument = GetParentDocument();
  if (!parentDocument) {
    return FlashClassification::Denied;
  }

  FlashClassification parentClassification =
      parentDocument->DocumentFlashClassification();

  if (parentClassification == FlashClassification::Denied) {
    return FlashClassification::Denied;
  }

  // Allow unknown children to inherit allowed status from parent, but
  // do not allow denied children to do so.
  if (classification == FlashClassification::Unknown &&
      parentClassification == FlashClassification::Allowed) {
    return FlashClassification::Allowed;
  }

  return classification;
}

void Document::ClearStaleServoData() {
  DocumentStyleRootIterator iter(this);
  while (Element* root = iter.GetNextStyleRoot()) {
    RestyleManager::ClearServoDataFromSubtree(root);
  }
}

Selection* Document::GetSelection(ErrorResult& aRv) {
  nsCOMPtr<nsPIDOMWindowInner> window = GetInnerWindow();
  if (!window) {
    return nullptr;
  }

  if (!window->IsCurrentInnerWindow()) {
    return nullptr;
  }

  return nsGlobalWindowInner::Cast(window)->GetSelection(aRv);
}

already_AddRefed<mozilla::dom::Promise> Document::HasStorageAccess(
    mozilla::ErrorResult& aRv) {
  nsIGlobalObject* global = GetScopeObject();
  if (!global) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  RefPtr<Promise> promise =
      Promise::Create(global, aRv, Promise::ePropagateUserInteraction);
  if (aRv.Failed()) {
    return nullptr;
  }

  if (NodePrincipal()->GetIsNullPrincipal()) {
    promise->MaybeResolve(false);
    return promise.forget();
  }

  if (IsTopLevelContentDocument()) {
    promise->MaybeResolve(true);
    return promise.forget();
  }

  nsCOMPtr<Document> topLevelDoc = GetTopLevelContentDocument();
  if (!topLevelDoc) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }
  if (topLevelDoc->NodePrincipal()->Equals(NodePrincipal())) {
    promise->MaybeResolve(true);
    return promise.forget();
  }

  nsPIDOMWindowInner* inner = GetInnerWindow();
  nsGlobalWindowOuter* outer = nullptr;
  if (inner) {
    outer = nsGlobalWindowOuter::Cast(inner->GetOuterWindow());
    promise->MaybeResolve(outer->HasStorageAccess());
  } else {
    promise->MaybeRejectWithUndefined();
  }
  return promise.forget();
}

already_AddRefed<mozilla::dom::Promise> Document::RequestStorageAccess(
    mozilla::ErrorResult& aRv) {
  nsIGlobalObject* global = GetScopeObject();
  if (!global) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return nullptr;
  }

  // Propagate user input event handling to the resolve handler
  RefPtr<Promise> promise =
      Promise::Create(global, aRv, Promise::ePropagateUserInteraction);
  if (aRv.Failed()) {
    return nullptr;
  }

  // Step 1. If the document already has been granted access, resolve.
  nsCOMPtr<nsPIDOMWindowInner> inner = GetInnerWindow();
  RefPtr<nsGlobalWindowOuter> outer;
  if (inner) {
    outer = nsGlobalWindowOuter::Cast(inner->GetOuterWindow());
    if (outer->HasStorageAccess()) {
      promise->MaybeResolveWithUndefined();
      return promise.forget();
    }
  }

  // Step 2. If the document has a null origin, reject.
  if (NodePrincipal()->GetIsNullPrincipal()) {
    promise->MaybeRejectWithUndefined();
    return promise.forget();
  }

  // Only enforce third-party checks when there is a reason to enforce them.
  if (CookieSettings()->GetCookieBehavior() !=
      nsICookieService::BEHAVIOR_REJECT_TRACKER) {
    // Step 3. If the document's frame is the main frame, resolve.
    if (IsTopLevelContentDocument()) {
      promise->MaybeResolveWithUndefined();
      return promise.forget();
    }

    // Step 4. If the sub frame's origin is equal to the main frame's, resolve.
    nsCOMPtr<Document> topLevelDoc = GetTopLevelContentDocument();
    if (!topLevelDoc) {
      aRv.Throw(NS_ERROR_NOT_AVAILABLE);
      return nullptr;
    }
    if (topLevelDoc->NodePrincipal()->Equals(NodePrincipal())) {
      promise->MaybeResolveWithUndefined();
      return promise.forget();
    }
  }

  // Step 5. If the sub frame is not sandboxed, skip to step 7.
  // Step 6. If the sub frame doesn't have the token
  //         "allow-storage-access-by-user-activation", reject.
  if (StorageAccessSandboxed()) {
    promise->MaybeRejectWithUndefined();
    return promise.forget();
  }

  // Step 7. If the sub frame's parent frame is not the top frame, reject.
  Document* parent = GetParentDocument();
  if (parent && !parent->IsTopLevelContentDocument()) {
    promise->MaybeRejectWithUndefined();
    return promise.forget();
  }

  // Step 8. If the browser is not processing a user gesture, reject.
  if (!EventStateManager::IsHandlingUserInput()) {
    promise->MaybeRejectWithUndefined();
    return promise.forget();
  }

  // Step 9. Check any additional rules that the browser has.
  //         Examples: Whitelists, blacklists, on-device classification,
  //         user settings, anti-clickjacking heuristics, or prompting the
  //         user for explicit permission. Reject if some rule is not fulfilled.

  if (nsContentUtils::IsInPrivateBrowsing(this)) {
    // If the document is in PB mode, it doesn't have access to its persistent
    // cookie jar, so reject the promise here.
    promise->MaybeRejectWithUndefined();
    return promise.forget();
  }

  if (CookieSettings()->GetCookieBehavior() ==
          nsICookieService::BEHAVIOR_REJECT_TRACKER &&
      inner) {
    // Only do something special for third-party tracking content.
    if (nsContentUtils::StorageDisabledByAntiTracking(this, nullptr)) {
      // Note: If this has returned true, the top-level document is guaranteed
      // to not be on the Content Blocking allow list.
      DebugOnly<bool> isOnAllowList = false;
      // If we have a parent document, it has to be non-private since we
      // verified earlier that our own document is non-private and a private
      // document can never have a non-private document as its child.
      MOZ_ASSERT_IF(parent, !nsContentUtils::IsInPrivateBrowsing(parent));
      MOZ_ASSERT_IF(
          NS_SUCCEEDED(AntiTrackingCommon::IsOnContentBlockingAllowList(
              parent->GetDocumentURI(), false,
              AntiTrackingCommon::eStorageChecks, isOnAllowList)),
          !isOnAllowList);

      auto performFinalChecks = [inner]()
          -> RefPtr<AntiTrackingCommon::StorageAccessFinalCheckPromise> {
        RefPtr<AntiTrackingCommon::StorageAccessFinalCheckPromise::Private> p =
            new AntiTrackingCommon::StorageAccessFinalCheckPromise::Private(
                __func__);
        RefPtr<StorageAccessPermissionRequest> sapr =
            StorageAccessPermissionRequest::Create(
                inner,
                // Allow
                [p] { p->Resolve(AntiTrackingCommon::eAllow, __func__); },
                // Allow auto grant
                [p] {
                  p->Resolve(AntiTrackingCommon::eAllowAutoGrant, __func__);
                },
                // Allow on any site
                [p] {
                  p->Resolve(AntiTrackingCommon::eAllowOnAnySite, __func__);
                },
                // Block
                [p] { p->Reject(false, __func__); });

        typedef ContentPermissionRequestBase::PromptResult PromptResult;
        PromptResult pr = sapr->CheckPromptPrefs();
        bool onAnySite = false;
        if (pr == PromptResult::Pending) {
          // Also check our custom pref for the "Allow on any site" case
          if (Preferences::GetBool("dom.storage_access.prompt.testing",
                                   false) &&
              Preferences::GetBool(
                  "dom.storage_access.prompt.testing.allowonanysite", false)) {
            pr = PromptResult::Granted;
            onAnySite = true;
          }
        }

        if (pr != PromptResult::Pending) {
          MOZ_ASSERT_IF(pr != PromptResult::Granted,
                        pr == PromptResult::Denied);
          if (pr == PromptResult::Granted) {
            return AntiTrackingCommon::StorageAccessFinalCheckPromise::
                CreateAndResolve(onAnySite ? AntiTrackingCommon::eAllowOnAnySite
                                           : AntiTrackingCommon::eAllow,
                                 __func__);
          }
          return AntiTrackingCommon::StorageAccessFinalCheckPromise::
              CreateAndReject(false, __func__);
        }

        sapr->RequestDelayedTask(
            inner->EventTargetFor(TaskCategory::Other),
            ContentPermissionRequestBase::DelayedTaskType::Request);
        return p.forget();
      };
      AntiTrackingCommon::AddFirstPartyStorageAccessGrantedFor(
          NodePrincipal(), inner, AntiTrackingCommon::eStorageAccessAPI,
          performFinalChecks)
          ->Then(
              GetCurrentThreadSerialEventTarget(), __func__,
              [outer, promise] {
                // Step 10. Grant the document access to cookies and store
                // that fact for
                //          the purposes of future calls to
                //          hasStorageAccess() and requestStorageAccess().
                outer->SetHasStorageAccess(true);
                promise->MaybeResolveWithUndefined();
              },
              [outer, promise] {
                outer->SetHasStorageAccess(false);
                promise->MaybeRejectWithUndefined();
              });

      return promise.forget();
    }
  }

  outer->SetHasStorageAccess(true);
  promise->MaybeResolveWithUndefined();
  return promise.forget();
}

void Document::RecordNavigationTiming(ReadyState aReadyState) {
  if (!XRE_IsContentProcess()) {
    return;
  }
  if (!IsTopLevelContentDocument()) {
    return;
  }
  // If we dont have the timing yet (mostly because the doc is still loading),
  // get it from docshell.
  RefPtr<nsDOMNavigationTiming> timing = mTiming;
  if (!timing) {
    if (!mDocumentContainer) {
      return;
    }
    timing = mDocumentContainer->GetNavigationTiming();
    if (!timing) {
      return;
    }
  }
  TimeStamp startTime = timing->GetNavigationStartTimeStamp();
  switch (aReadyState) {
    case READYSTATE_LOADING:
      if (!mDOMLoadingSet) {
        Telemetry::AccumulateTimeDelta(Telemetry::TIME_TO_DOM_LOADING_MS,
                                       startTime);
        mDOMLoadingSet = true;
      }
      break;
    case READYSTATE_INTERACTIVE:
      if (!mDOMInteractiveSet) {
        Telemetry::AccumulateTimeDelta(Telemetry::TIME_TO_DOM_INTERACTIVE_MS,
                                       startTime);
        mDOMInteractiveSet = true;
      }
      break;
    case READYSTATE_COMPLETE:
      if (!mDOMCompleteSet) {
        Telemetry::AccumulateTimeDelta(Telemetry::TIME_TO_DOM_COMPLETE_MS,
                                       startTime);
        mDOMCompleteSet = true;
      }
      break;
    default:
      NS_WARNING("Unexpected ReadyState value");
      break;
  }
}

bool Document::ModuleScriptsEnabled() {
  static bool sEnabledForContent = false;
  static bool sCachedPref = false;
  if (!sCachedPref) {
    sCachedPref = true;
    Preferences::AddBoolVarCache(&sEnabledForContent,
                                 "dom.moduleScripts.enabled", false);
  }

  return nsContentUtils::IsChromeDoc(this) || sEnabledForContent;
}

void Document::ReportShadowDOMUsage() {
  if (mHasReportedShadowDOMUsage) {
    return;
  }

  Document* topLevel = GetTopLevelContentDocument();
  if (topLevel && !topLevel->mHasReportedShadowDOMUsage) {
    topLevel->mHasReportedShadowDOMUsage = true;
    nsString uri;
    Unused << topLevel->GetDocumentURI(uri);
    if (!uri.IsEmpty()) {
      nsAutoString msg = NS_LITERAL_STRING("Shadow DOM used in [") + uri +
                         NS_LITERAL_STRING("] or in some of its subdocuments.");
      nsContentUtils::ReportToConsoleNonLocalized(
          msg, nsIScriptError::infoFlag, NS_LITERAL_CSTRING("DOM"), topLevel);
    }
  }

  mHasReportedShadowDOMUsage = true;
}

bool Document::StorageAccessSandboxed() const {
  return StaticPrefs::dom_storage_access_enabled() &&
         (GetSandboxFlags() & SANDBOXED_STORAGE_ACCESS) != 0;
}

bool Document::GetCachedSizes(nsTabSizes* aSizes) {
  if (mCachedTabSizeGeneration == 0 ||
      GetGeneration() != mCachedTabSizeGeneration) {
    return false;
  }
  aSizes->mDom += mCachedTabSizes.mDom;
  aSizes->mStyle += mCachedTabSizes.mStyle;
  aSizes->mOther += mCachedTabSizes.mOther;
  return true;
}

void Document::SetCachedSizes(nsTabSizes* aSizes) {
  mCachedTabSizes.mDom = aSizes->mDom;
  mCachedTabSizes.mStyle = aSizes->mStyle;
  mCachedTabSizes.mOther = aSizes->mOther;
  mCachedTabSizeGeneration = GetGeneration();
}

already_AddRefed<nsAtom> Document::GetContentLanguageAsAtomForStyle() const {
  nsAutoString contentLang;
  GetContentLanguage(contentLang);
  contentLang.StripWhitespace();

  // Content-Language may be a comma-separated list of language codes,
  // in which case the HTML5 spec says to treat it as unknown
  if (!contentLang.IsEmpty() && !contentLang.Contains(char16_t(','))) {
    return NS_Atomize(contentLang);
  }

  return nullptr;
}

already_AddRefed<nsAtom> Document::GetLanguageForStyle() const {
  RefPtr<nsAtom> lang = GetContentLanguageAsAtomForStyle();
  if (!lang) {
    lang = mLanguageFromCharset;
  }
  return lang.forget();
}

const LangGroupFontPrefs* Document::GetFontPrefsForLang(
    nsAtom* aLanguage, bool* aNeedsToCache) const {
  nsAtom* lang = aLanguage ? aLanguage : mLanguageFromCharset.get();
  return StaticPresData::Get()->GetFontPrefsForLang(lang, aNeedsToCache);
}

void Document::DoCacheAllKnownLangPrefs() {
  MOZ_ASSERT(mMayNeedFontPrefsUpdate);
  RefPtr<nsAtom> lang = GetLanguageForStyle();
  StaticPresData* data = StaticPresData::Get();
  data->GetFontPrefsForLang(lang ? lang.get() : mLanguageFromCharset.get());
  data->GetFontPrefsForLang(nsGkAtoms::x_math);
  // https://bugzilla.mozilla.org/show_bug.cgi?id=1362599#c12
  data->GetFontPrefsForLang(nsGkAtoms::Unicode);
  for (auto iter = mLanguagesUsed.Iter(); !iter.Done(); iter.Next()) {
    data->GetFontPrefsForLang(iter.Get()->GetKey());
  }
  mMayNeedFontPrefsUpdate = false;
}

void Document::RecomputeLanguageFromCharset() {
  nsLanguageAtomService* service = nsLanguageAtomService::GetService();
  RefPtr<nsAtom> language = service->LookupCharSet(mCharacterSet);
  if (language == nsGkAtoms::Unicode) {
    language = service->GetLocaleLanguage();
  }

  if (language == mLanguageFromCharset) {
    return;
  }

  mMayNeedFontPrefsUpdate = true;
  mLanguageFromCharset = language.forget();
}

nsICookieSettings* Document::CookieSettings() {
  // If we are here, this is probably a javascript: URL document. In any case,
  // we must have a nsCookieSettings. Let's create it.
  if (!mCookieSettings) {
    mCookieSettings = net::CookieSettings::Create();
  }

  return mCookieSettings;
}

nsIPrincipal* Document::EffectiveStoragePrincipal() const {
  if (!StaticPrefs::privacy_storagePrincipal_enabledForTrackers()) {
    return NodePrincipal();
  }

  nsContentUtils::StorageAccess access =
      nsContentUtils::StorageAllowedForDocument(this);

  // Let's use the storage principal only if we need to partition the cookie
  // jar. When the permission is granted, access will be different and the
  // normal principal will be used.
  if (access != nsContentUtils::StorageAccess::ePartitionedOrDeny) {
    return NodePrincipal();
  }

  return mIntrinsicStoragePrincipal;
}

}  // namespace dom
}  // namespace mozilla