Deliver IPC messages together with SwapCompositorFrame

content/public/browser/web_contents_observer.h

Index: content/public/browser/web_contents_observer.h
diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
index 9fae539faf6e3a97c3198e6d95a3e703202a7982..ae80d1ca6ee76a57b5577eef7c45d9fd83f57b01 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -240,6 +240,7 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   // This method is invoked when the renderer has completed its first paint
   // after a non-empty layout.
   virtual void DidFirstVisuallyNonEmptyPaint(int32 page_id) {}
+  virtual void OnSourceFrameNumber(int source_frame_number, int tag) {}
 
   // These two methods correspond to the points in time when the spinner of the
   // tab starts and stops spinning.
@@ -332,6 +333,8 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   virtual void AccessibilityEventReceived(
       const std::vector<AXEventNotificationDetails>& details) {}
 
+  virtual bool DispatchMessageWithSwapFrame(const IPC::Message& message) {}

[mkosiba (inactive), 2014/05/06 22:30:33]

this is where subclasses from different layers (think chrome/ vs
android_webview/) would hook in.

+
   // IPC::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;