Bug 1500257 part 4 - Modify nsFrameLoader to create PRemoteFrame when enabled via pref and attribute. r=qdot

This commit hooks up nsFrameLoader in the child process to use the
PRemoteFrame protocol to support remote iframes. This is only activated
when a special pref is set, and the iframe has a marker attribute on it.

For example:
<iframe fission/>

In the future, we should unify nsFrameLoader to operate on a common
interface between the parent process top-level browser, and child
process subframe case. This commit just adds a new member that can
be used instead of mRemoteBrowser, when appropriate. IsRemoteFrame()
will return true for both cases.

Differential Revision: https://phabricator.services.mozilla.com/D17444

--HG--
extra : source : e33b9de7283e5fb6441e118b25af8d4ac3411bf2
extra : intermediate-source : 697a9159e0d260118ee6ebd34948d187a8c5359f

dom/base/nsFrameLoader.cpp

@@ -101,6 +101,8 @@
 #include "mozilla/dom/ParentSHistory.h"
 #include "mozilla/dom/ChildSHistory.h"
 #include "mozilla/dom/CanonicalBrowsingContext.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/RemoteFrameChild.h"
 
 #include "mozilla/dom/HTMLBodyElement.h"
 
@@ -349,7 +351,7 @@ nsresult nsFrameLoader::ReallyStartLoadingInternal() {
   AUTO_PROFILER_LABEL("nsFrameLoader::ReallyStartLoadingInternal", OTHER);
 
   if (IsRemoteFrame()) {
-    if (!mRemoteBrowser && !TryRemoteBrowser()) {
+    if (!mRemoteBrowser && !mRemoteFrameChild && !TryRemoteBrowser()) {
       NS_WARNING("Couldn't create child process for iframe.");
       return NS_ERROR_FAILURE;
     }
@@ -790,7 +792,7 @@ bool nsFrameLoader::ShowRemoteFrame(const ScreenIntSize& size,
   NS_ASSERTION(IsRemoteFrame(),
                "ShowRemote only makes sense on remote frames.");
 
-  if (!mRemoteBrowser && !TryRemoteBrowser()) {
+  if (!mRemoteBrowser && !mRemoteFrameChild && !TryRemoteBrowser()) {
     NS_ERROR("Couldn't create child process.");
     return false;
   }
@@ -1648,6 +1650,11 @@ void nsFrameLoader::DestroyDocShell() {
     mRemoteBrowser->Destroy();
   }
 
+  if (mRemoteFrameChild) {
+    Unused << mRemoteFrameChild->Send__delete__(mRemoteFrameChild);
+    mRemoteFrameChild = nullptr;
+  }
+
   // Fire the "unload" event if we're in-process.
   if (mChildMessageManager) {
     mChildMessageManager->FireUnloadEvent();
@@ -1689,6 +1696,11 @@ void nsFrameLoader::DestroyComplete() {
     mRemoteBrowser = nullptr;
   }
 
+  if (mRemoteFrameChild) {
+    Unused << mRemoteFrameChild->Send__delete__(mRemoteFrameChild);
+    mRemoteFrameChild = nullptr;
+  }
+
   if (mMessageManager) {
     mMessageManager->Disconnect();
   }
@@ -1764,6 +1776,13 @@ bool nsFrameLoader::ShouldUseRemoteProcess() {
     return false;
   }
 
+  // Check if the force fission test attribute is enabled.
+  if (XRE_IsContentProcess() &&
+      Preferences::GetBool("browser.fission.oopif.attribute", false) &&
+      mOwnerContent->HasAttr(kNameSpaceID_None, nsGkAtoms::fission)) {
+    return true;
+  }
+
   if (XRE_IsContentProcess() &&
       !(PR_GetEnv("MOZ_NESTED_OOP_TABS") ||
         Preferences::GetBool("dom.ipc.tabs.nested.enabled", false))) {
@@ -1785,14 +1804,6 @@ bool nsFrameLoader::ShouldUseRemoteProcess() {
                                     nsGkAtoms::_true, eCaseMatters);
 }
 
-bool nsFrameLoader::IsRemoteFrame() {
-  if (mRemoteFrame) {
-    MOZ_ASSERT(!mDocShell, "Found a remote frame with a DocShell");
-    return true;
-  }
-  return false;
-}
-
 static already_AddRefed<BrowsingContext> CreateBrowsingContext(
     BrowsingContext* aParentContext, BrowsingContext* aOpenerContext,
     const nsAString& aName, bool aIsContent) {
@@ -2371,7 +2382,7 @@ static Tuple<ContentParent*, TabParent*> GetContentParent(Element* aBrowser) {
 }
 
 bool nsFrameLoader::TryRemoteBrowser() {
-  NS_ASSERTION(!mRemoteBrowser,
+  NS_ASSERTION(!mRemoteBrowser && !mRemoteFrameChild,
                "TryRemoteBrowser called with a remote browser already?");
 
   if (!mOwnerContent) {
@@ -2417,7 +2428,9 @@ bool nsFrameLoader::TryRemoteBrowser() {
   // iframes for JS plugins also get to skip these checks. We control the URL
   // that gets loaded, but the load is triggered from the document containing
   // the plugin.
-  if (!OwnerIsMozBrowserFrame() && !IsForJSPlugin()) {
+  // out of process iframes also get to skip this check.
+  if (!OwnerIsMozBrowserFrame() && !IsForJSPlugin() &&
+      !XRE_IsContentProcess()) {
     if (parentDocShell->ItemType() != nsIDocShellTreeItem::typeChrome) {
       // Allow about:addon an exception to this rule so it can load remote
       // extension options pages.
@@ -2487,6 +2500,14 @@ bool nsFrameLoader::TryRemoteBrowser() {
   }
 
   nsCOMPtr<Element> ownerElement = mOwnerContent;
+
+  // If we're in a content process, create a RemoteFrameChild actor.
+  if (XRE_IsContentProcess()) {
+    mRemoteFrameChild = RemoteFrameChild::Create(
+        this, context, NS_LITERAL_STRING(DEFAULT_REMOTE_TYPE));
+    return !!mRemoteFrameChild;
+  }
+
   mRemoteBrowser =
       ContentParent::CreateBrowser(context, ownerElement, openerContentParent,
                                    sameTabGroupAs, nextTabParentId);
@@ -2546,6 +2567,14 @@ bool nsFrameLoader::TryRemoteBrowser() {
   return true;
 }
 
+bool nsFrameLoader::IsRemoteFrame() {
+  if (mRemoteFrame) {
+    MOZ_ASSERT(!mDocShell, "Found a remote frame with a DocShell");
+    return true;
+  }
+  return false;
+}
+
 mozilla::dom::PBrowserParent* nsFrameLoader::GetRemoteBrowser() const {
   return mRemoteBrowser;
 }

dom/base/nsFrameLoader.h

@@ -58,6 +58,7 @@ class ProcessMessageManager;
 class Promise;
 class TabParent;
 class MutableTabContext;
+class RemoteFrameChild;
 
 namespace ipc {
 class StructuredCloneData;
@@ -270,6 +271,18 @@ class nsFrameLoader final : public nsStubMutationObserver,
     return mOwnerContent ? mOwnerContent->OwnerDoc() : nullptr;
   }
 
+  /**
+   * Returns whether this frame is a remote frame.
+   *
+   * This is true for either a top-level remote browser in the parent process,
+   * or a remote subframe in the child process.
+   */
+  bool IsRemoteFrame();
+
+  /**
+   * Returns the IPDL actor used if this is a top-level remote browser, or null
+   * otherwise.
+   */
   PBrowserParent* GetRemoteBrowser() const;
 
   /**
@@ -358,11 +371,6 @@ class nsFrameLoader final : public nsStubMutationObserver,
 
   bool ShouldUseRemoteProcess();
 
-  /**
-   * Return true if the frame is a remote frame. Return false otherwise
-   */
-  bool IsRemoteFrame();
-
   bool IsForJSPlugin() { return mJSPluginID != nsFakePluginTag::NOT_JSPLUGIN; }
 
   /**
@@ -456,6 +464,9 @@ class nsFrameLoader final : public nsStubMutationObserver,
   TabParent* mRemoteBrowser;
   uint64_t mChildID;
 
+  // This is used when this refers to a remote sub frame
+  RefPtr<mozilla::dom::RemoteFrameChild> mRemoteFrameChild;
+
   int32_t mJSPluginID;
 
   // Holds the last known size of the frame.

xpcom/ds/StaticAtoms.py

@@ -424,6 +424,7 @@ STATIC_ATOMS = [
     Atom("figure", "figure"),
     Atom("findbar", "findbar"),
     Atom("fixed", "fixed"),
+    Atom("fission", "fission"),
     Atom("flags", "flags"),
     Atom("flex", "flex"),
     Atom("flip", "flip"),