cc: Make scheduling be driven by vsync for android webview.

cc/trees/thread_proxy.h

Index: cc/trees/thread_proxy.h
diff --git a/cc/trees/thread_proxy.h b/cc/trees/thread_proxy.h
index 51cc18cd95fc6c89d86f6b48c38cb818ea64a32b..197269534f548a8db3285f4e7786e6a6082192e6 100644
--- a/cc/trees/thread_proxy.h
+++ b/cc/trees/thread_proxy.h
@@ -210,6 +210,7 @@ class CC_EXPORT ThreadProxy : public Proxy,
   void DidActivateSyncTree() override;
   void DidPrepareTiles() override;
   void DidCompletePageScaleAnimationOnImplThread() override;
+  void OnDrawForOutputSurface() override;
 
   // SchedulerClient implementation
   void WillBeginImplFrame(const BeginFrameArgs& args) override;
@@ -221,6 +222,7 @@ class CC_EXPORT ThreadProxy : public Proxy,
   void ScheduledActionActivateSyncTree() override;
   void ScheduledActionBeginOutputSurfaceCreation() override;
   void ScheduledActionPrepareTiles() override;
+  void ScheduledActionInvalidateOutputSurface() override;
   void DidAnticipatedDrawTimeChange(base::TimeTicks time) override;
   base::TimeDelta DrawDurationEstimate() override;
   base::TimeDelta BeginMainFrameToCommitDurationEstimate() override;