Bug 1518252 - Block layout on Fluent. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D17334

--HG--
extra : moz-landing-system : lando

dom/base/Document.cpp

@@ -1339,7 +1339,8 @@ Document::Document(const char* aContentType)
       mThrowOnDynamicMarkupInsertionCounter(0),
       mIgnoreOpensDuringUnloadCounter(0),
       mDocLWTheme(Doc_Theme_Uninitialized),
-      mSavedResolution(1.0f) {
+      mSavedResolution(1.0f),
+      mPendingInitialTranslation(false) {
   MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p created", this));
 
   SetIsInDocument();
@@ -3131,6 +3132,8 @@ void Document::LocalizationLinkAdded(Element* aLinkElement) {
     // will be resolved once the end of l10n resource
     // container is reached.
     mL10nResources.AppendElement(href);
+
+    mPendingInitialTranslation = true;
   }
 }
 
@@ -3173,11 +3176,30 @@ void Document::OnL10nResourceContainerParsed() {
 }
 
 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;
+
+  nsCOMPtr<nsIContentSink> sink;
+  if (mParser) {
+    sink = mParser->GetContentSink();
+  } else {
+    sink = do_QueryReferent(mWeakSink);
+  }
+  if (sink) {
+    sink->InitialDocumentTranslationCompleted();
+  }
+}
+
 bool Document::IsWebAnimationsEnabled(JSContext* aCx, JSObject* /*unused*/) {
   MOZ_ASSERT(NS_IsMainThread());
 
@@ -8141,7 +8163,6 @@ void Document::SetReadyStateInternal(ReadyState rs) {
         mXULPersist->Init();
       }
     }
-    TriggerInitialDocumentTranslation();
   }
 
   RecordNavigationTiming(rs);

dom/base/Document.h

@@ -3425,13 +3425,12 @@ class Document : public nsINode,
    */
   void LocalizationLinkRemoved(Element* aLinkElement);
 
- protected:
   /**
-   * This method should be collect as soon as the
+   * This method should be called as soon as the
    * parsing of the document is completed.
    *
-   * In HTML this happens when readyState becomes
-   * `interactive`.
+   * In HTML/XHTML this happens when we finish parsing
+   * the document element.
    * In XUL it happens at `DoneWalking`, during
    * `MozBeforeInitialXULLayout`.
    *
@@ -3440,6 +3439,18 @@ class Document : public nsINode,
    */
   void TriggerInitialDocumentTranslation();
 
+  /**
+   * This method is called when the initial translation
+   * of the document is completed.
+   *
+   * It unblocks the layout.
+   *
+   * This method is virtual so that XULDocument can
+   * override it.
+   */
+  virtual void InitialDocumentTranslationCompleted();
+
+ protected:
   RefPtr<mozilla::dom::DocumentL10n> mDocumentL10n;
 
  private:
@@ -4513,9 +4524,13 @@ class Document : public nsINode,
   // Pres shell resolution saved before entering fullscreen mode.
   float mSavedResolution;
 
+  bool mPendingInitialTranslation;
+
  public:
   // Needs to be public because the bindings code pokes at it.
   js::ExpandoAndGeneration mExpandoAndGeneration;
+
+  bool HasPendingInitialTranslation() { return mPendingInitialTranslation; }
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(Document, NS_IDOCUMENT_IID)

dom/base/nsContentSink.cpp

@@ -1170,8 +1170,9 @@ void nsContentSink::StartLayout(bool aIgnorePendingSheets) {
 
   mDeferredLayoutStart = true;
 
-  if (!aIgnorePendingSheets && WaitForPendingSheets()) {
-    // Bail out; we'll start layout when the sheets load
+  if (!aIgnorePendingSheets &&
+      (WaitForPendingSheets() || mDocument->HasPendingInitialTranslation())) {
+    // Bail out; we'll start layout when the sheets and l10n load
     return;
   }
 

dom/xml/nsXMLContentSink.cpp

@@ -1073,6 +1073,8 @@ nsresult nsXMLContentSink::HandleEndElement(const char16_t* aName,
     // probably need to deal here.... (and stop appending them on open).
     mState = eXMLContentSinkState_InEpilog;
 
+    mDocument->TriggerInitialDocumentTranslation();
+
     // We might have had no occasion to start layout yet.  Do so now.
     MaybeStartLayout(false);
   }
@@ -1407,6 +1409,10 @@ nsresult nsXMLContentSink::AddText(const char16_t* aText, int32_t aLength) {
   return NS_OK;
 }
 
+void nsXMLContentSink::InitialDocumentTranslationCompleted() {
+  StartLayout(false);
+}
+
 void nsXMLContentSink::FlushPendingNotifications(FlushType aType) {
   // Only flush tags if we're not doing the notification ourselves
   // (since we aren't reentrant)

dom/xml/nsXMLContentSink.h

@@ -67,6 +67,7 @@ class nsXMLContentSink : public nsContentSink,
   NS_IMETHOD WillInterrupt(void) override;
   NS_IMETHOD WillResume(void) override;
   NS_IMETHOD SetParser(nsParserBase* aParser) override;
+  virtual void InitialDocumentTranslationCompleted() override;
   virtual void FlushPendingNotifications(mozilla::FlushType aType) override;
   virtual void SetDocumentCharset(NotNull<const Encoding*> aEncoding) override;
   virtual nsISupports* GetTarget() override;

dom/xul/XULDocument.cpp

@@ -449,6 +449,11 @@ void XULDocument::AddElementToDocumentPost(Element* aElement) {
   }
 }
 
+void XULDocument::InitialDocumentTranslationCompleted() {
+  mPendingInitialTranslation = false;
+  MaybeDoneWalking();
+}
+
 void XULDocument::AddSubtreeToDocument(nsIContent* aContent) {
   MOZ_ASSERT(aContent->GetComposedDoc() == this, "Element not in doc!");
 
@@ -958,15 +963,26 @@ nsresult XULDocument::ResumeWalk() {
   mXULPersist->Init();
 
   mStillWalking = false;
-  if (mPendingSheets == 0) {
-    rv = DoneWalking();
+  return MaybeDoneWalking();
+}
+
+nsresult XULDocument::MaybeDoneWalking() {
+  if (mPendingSheets > 0 || mStillWalking) {
+    return NS_OK;
   }
-  return rv;
+
+  if (mPendingInitialTranslation) {
+    TriggerInitialDocumentTranslation();
+    return NS_OK;
+  }
+
+  return DoneWalking();
 }
 
 nsresult XULDocument::DoneWalking() {
   MOZ_ASSERT(mPendingSheets == 0, "there are sheets to be loaded");
   MOZ_ASSERT(!mStillWalking, "walk not done");
+  MOZ_ASSERT(!mPendingInitialTranslation, "translation pending");
 
   // XXXldb This is where we should really be setting the chromehidden
   // attribute.
@@ -983,18 +999,10 @@ nsresult XULDocument::DoneWalking() {
 
     NotifyPossibleTitleChange(false);
 
-    // For performance reasons, we want to trigger the DocumentL10n's
-    // `TriggerInitialDocumentTranslation` within the same microtask that will
-    // be created for a `MozBeforeInitialXULLayout` event listener.
-    AddEventListener(NS_LITERAL_STRING("MozBeforeInitialXULLayout"),
-                     mDocumentL10n, true, false);
-
     nsContentUtils::DispatchTrustedEvent(
         this, ToSupports(this), NS_LITERAL_STRING("MozBeforeInitialXULLayout"),
         CanBubble::eYes, Cancelable::eNo);
 
-    RemoveEventListener(NS_LITERAL_STRING("MozBeforeInitialXULLayout"),
-                        mDocumentL10n, true);
 
     // 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
@@ -1039,9 +1047,7 @@ XULDocument::StyleSheetLoaded(StyleSheet* aSheet, bool aWasDeferred,
 
     --mPendingSheets;
 
-    if (!mStillWalking && mPendingSheets == 0) {
-      return DoneWalking();
-    }
+    return MaybeDoneWalking();
   }
 
   return NS_OK;

dom/xul/XULDocument.h

@@ -76,6 +76,8 @@ class XULDocument final : public XMLDocument,
 
   virtual void EndLoad() override;
 
+  virtual void InitialDocumentTranslationCompleted() override;
+
   // nsIMutationObserver interface
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
@@ -296,7 +298,15 @@ class XULDocument final : public XMLDocument,
   nsresult ResumeWalk();
 
   /**
-   * Called at the end of ResumeWalk() and from StyleSheetLoaded().
+   * Called at the end of ResumeWalk(), from StyleSheetLoaded(),
+   * and from DocumentL10n.
+   * If walking, stylesheets and l10n are not blocking, it
+   * will trigger `DoneWalking()`.
+   */
+  nsresult MaybeDoneWalking();
+
+  /**
+   * Called from `MaybeDoneWalking()`.
    * Expects that both the prototype document walk is complete and
    * all referenced stylesheets finished loading.
    */

intl/l10n/DocumentL10n.cpp

@@ -8,7 +8,6 @@
 #include "mozilla/dom/DocumentL10n.h"
 #include "mozilla/dom/DocumentL10nBinding.h"
 #include "mozilla/dom/Element.h"
-#include "mozilla/dom/Event.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/PromiseNativeHandler.h"
 #include "nsQueryObject.h"
@@ -60,18 +59,12 @@ void PromiseResolver::RejectedCallback(JSContext* aCx,
 
 PromiseResolver::~PromiseResolver() { mPromise = nullptr; }
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DocumentL10n)
-  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
-  NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
-NS_INTERFACE_MAP_END
-
-NS_IMPL_CYCLE_COLLECTING_ADDREF(DocumentL10n)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(DocumentL10n)
-
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DocumentL10n, mDocument, mDOMLocalization,
                                       mReady)
 
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(DocumentL10n, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(DocumentL10n, Release)
+
 DocumentL10n::DocumentL10n(Document* aDocument)
     : mDocument(aDocument), mState(DocumentL10nState::Initialized) {}
 
@@ -140,19 +133,6 @@ already_AddRefed<Promise> DocumentL10n::MaybeWrapPromise(
   return docPromise.forget();
 }
 
-NS_IMETHODIMP
-DocumentL10n::HandleEvent(Event* aEvent) {
-#ifdef DEBUG
-  nsAutoString eventType;
-  aEvent->GetType(eventType);
-  MOZ_ASSERT(eventType.EqualsLiteral("MozBeforeInitialXULLayout"));
-#endif
-
-  TriggerInitialDocumentTranslation();
-
-  return NS_OK;
-}
-
 uint32_t DocumentL10n::AddResourceIds(nsTArray<nsString>& aResourceIds) {
   uint32_t ret = 0;
   mDOMLocalization->AddResourceIds(aResourceIds, false, &ret);
@@ -312,13 +292,16 @@ class L10nReadyHandler final : public PromiseNativeHandler {
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_CLASS(L10nReadyHandler)
 
-  explicit L10nReadyHandler(Promise* aPromise) : mPromise(aPromise) {}
+  explicit L10nReadyHandler(Promise* aPromise, Document* aDocument)
+      : mPromise(aPromise), mDocument(aDocument) {}
 
   void ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override {
+    mDocument->InitialDocumentTranslationCompleted();
     mPromise->MaybeResolveWithUndefined();
   }
 
   void RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override {
+    mDocument->InitialDocumentTranslationCompleted();
     mPromise->MaybeRejectWithUndefined();
   }
 
@@ -326,6 +309,7 @@ class L10nReadyHandler final : public PromiseNativeHandler {
   ~L10nReadyHandler() = default;
 
   RefPtr<Promise> mPromise;
+  RefPtr<Document> mDocument;
 };
 
 NS_IMPL_CYCLE_COLLECTION(L10nReadyHandler, mPromise)
@@ -351,7 +335,8 @@ void DocumentL10n::TriggerInitialDocumentTranslation() {
 
   RefPtr<Promise> promise;
   mDOMLocalization->TranslateRoots(getter_AddRefs(promise));
-  RefPtr<PromiseNativeHandler> l10nReadyHandler = new L10nReadyHandler(mReady);
+  RefPtr<PromiseNativeHandler> l10nReadyHandler =
+      new L10nReadyHandler(mReady, mDocument);
   promise->AppendNativeHandler(l10nReadyHandler);
 }
 

intl/l10n/DocumentL10n.h

@@ -11,7 +11,6 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/dom/BindingDeclarations.h"
-#include "nsIDOMEventListener.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsWrapperCache.h"
 #include "mozilla/dom/Document.h"
@@ -53,11 +52,10 @@ enum class DocumentL10nState { Initialized = 0, InitialTranslationTriggered };
  * instance of mozIDOMLocalization and maintains a single promise
  * which gets resolved the first time the document gets translated.
  */
-class DocumentL10n final : public nsIDOMEventListener, public nsWrapperCache {
+class DocumentL10n final : public nsWrapperCache {
  public:
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DocumentL10n)
-  NS_DECL_NSIDOMEVENTLISTENER
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(DocumentL10n)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(DocumentL10n)
 
  public:
   explicit DocumentL10n(Document* aDocument);

parser/html/nsHtml5TreeOpExecutor.cpp

@@ -170,6 +170,7 @@ nsHtml5TreeOpExecutor::DidBuildModel(bool aTerminated) {
     }
 
     if (!destroying) {
+      mDocument->TriggerInitialDocumentTranslation();
       nsContentSink::StartLayout(false);
     }
   }
@@ -228,6 +229,10 @@ nsHtml5TreeOpExecutor::SetParser(nsParserBase* aParser) {
   return NS_OK;
 }
 
+void nsHtml5TreeOpExecutor::InitialDocumentTranslationCompleted() {
+  nsContentSink::StartLayout(false);
+}
+
 void nsHtml5TreeOpExecutor::FlushPendingNotifications(FlushType aType) {
   if (aType >= FlushType::EnsurePresShellInitAndFrames) {
     // Bug 577508 / 253951

parser/html/nsHtml5TreeOpExecutor.h

@@ -136,6 +136,8 @@ class nsHtml5TreeOpExecutor final
    */
   NS_IMETHOD WillResume() override;
 
+  virtual void InitialDocumentTranslationCompleted() override;
+
   /**
    * Sets the parser.
    */

parser/htmlparser/nsIContentSink.h

@@ -130,6 +130,8 @@ class nsIContentSink : public nsISupports {
    * Posts a runnable that continues parsing.
    */
   virtual void ContinueInterruptedParsingAsync() {}
+
+  virtual void InitialDocumentTranslationCompleted() {}
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsIContentSink, NS_ICONTENT_SINK_IID)