Implement WebCompositorOutputSurface

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 69535ad6c5f02d99cafc383bdcea703d02b15af1..f086ee278808d7dacb4b5a2f582e424438bd38f5 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -358,6 +358,10 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   // locked.
   bool GotResponseToLockMouseRequest(bool allowed);
 
+  // Tells the RenderWidget about the latest vsync parameters.
+  virtual void UpdateVSyncParameters(base::TimeTicks timebase,
+                                     base::TimeDelta interval);

[jbates, 2012/07/27 18:42:26]

If the interval is TimeDelta, it's limited to microsecond precision, which
equates to a dropped frame every ~5 minutes. I guess the timebase will give the
scheduler a chance to correct that drift though, but it's unclear whether all
platforms can get a timebase and how often we will update it. The DWM API gives
a numerator and denominator for the interval (for example: 60000 and 1001 on my
z600 box). How about changing the interval to uint32 numerator and uint32
denominator? That way the CC scheduler can have the best chance at maintaining
an accurate tick rate.

+
   // Called by the view in response to AcceleratedSurfaceBuffersSwapped or
   // AcceleratedSurfacePostSubBuffer.
   static void AcknowledgeBufferPresent(