Provide a vsync notification to the renderer

content/renderer/gpu/compositor_output_surface.h

Index: content/renderer/gpu/compositor_output_surface.h
diff --git a/content/renderer/gpu/compositor_output_surface.h b/content/renderer/gpu/compositor_output_surface.h
index ffc69650c6562a6384e553222f299f9a758792c5..5009199c2ba3338ed3cb526453eca2a1edd7395c 100644
--- a/content/renderer/gpu/compositor_output_surface.h
+++ b/content/renderer/gpu/compositor_output_surface.h
@@ -46,6 +46,7 @@ class CompositorOutputSurface
   virtual WebKit::WebGraphicsContext3D* Context3D() const OVERRIDE;
   virtual cc::SoftwareOutputDevice* SoftwareDevice() const OVERRIDE;
   virtual void SendFrameToParentCompositor(cc::CompositorFrame*) OVERRIDE;
+  virtual void EnableVSyncNotification(bool enable) OVERRIDE;
 
   // TODO(epenner): This seems out of place here and would be a better fit
   // int CompositorThread after it is fully refactored (http://crbug/170828)
@@ -75,6 +76,7 @@ class CompositorOutputSurface
   void OnMessageReceived(const IPC::Message& message);
   void OnUpdateVSyncParameters(
       base::TimeTicks timebase, base::TimeDelta interval);
+  void DidVSync(base::TimeTicks frame_time);
   bool Send(IPC::Message* message);
 
   scoped_refptr<IPC::ForwardingMessageFilter> output_surface_filter_;