Bug 570620, part m: Add API for attaching a "remote frame" to its corresponding nsFrameLoader, so that the frame can be found during painting. r=tn sr=smaug

content/base/src/nsFrameLoader.h

@@ -65,6 +65,10 @@ namespace dom {
 class PBrowserParent;
 class TabParent;
 }
+
+namespace layout {
+class RenderFrameParent;
+}
 }
 
 #ifdef MOZ_WIDGET_GTK2
@@ -81,6 +85,7 @@ class nsFrameLoader : public nsIFrameLoader
 #ifdef MOZ_IPC
   typedef mozilla::dom::PBrowserParent PBrowserParent;
   typedef mozilla::dom::TabParent TabParent;
+  typedef mozilla::layout::RenderFrameParent RenderFrameParent;
 #endif
 
 protected:
@@ -98,6 +103,7 @@ protected:
     , mDelayRemoteDialogs(PR_FALSE)
     , mRemoteBrowserShown(PR_FALSE)
     , mRemoteFrame(false)
+    , mCurrentRemoteFrame(nsnull)
     , mRemoteBrowser(nsnull)
 #endif
   {}
@@ -168,6 +174,35 @@ public:
 
 #ifdef MOZ_IPC
   PBrowserParent* GetRemoteBrowser();
+
+  /**
+   * The "current" render frame is the one on which the most recent
+   * remote layer-tree transaction was executed.  If no content has
+   * been drawn yet, or the remote browser doesn't have any drawn
+   * content for whatever reason, return NULL.  The returned render
+   * frame has an associated shadow layer tree.
+   *
+   * Note that the returned render frame might not be a frame
+   * constructed for this->GetURL().  This can happen, e.g., if the
+   * <browser> was just navigated to a new URL, but hasn't painted the
+   * new page yet.  A render frame for the previous page may be
+   * returned.  (In-process <browser> behaves similarly, and this
+   * behavior seems desirable.)
+   */
+  RenderFrameParent* GetCurrentRemoteFrame() const
+  {
+    return mCurrentRemoteFrame;
+  }
+
+  /**
+   * |aFrame| can be null.  If non-null, it must be the remote frame
+   * on which the most recent layer transaction completed for this's
+   * <browser>.
+   */
+  void SetCurrentRemoteFrame(RenderFrameParent* aFrame)
+  {
+    mCurrentRemoteFrame = aFrame;
+  }
 #endif
   nsFrameMessageManager* GetFrameMessageManager() { return mMessageManager; }
 
@@ -229,6 +264,7 @@ private:
   bool mRemoteFrame;
   // XXX leaking
   nsCOMPtr<nsIObserver> mChildHost;
+  RenderFrameParent* mCurrentRemoteFrame;
   TabParent* mRemoteBrowser;
 #endif