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

content/public/browser/android/synchronous_compositor.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
 #define CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
 
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "gpu/command_buffer/service/in_process_command_buffer.h"
@@ skipping 69 matching lines @@
   virtual bool DemandDrawSw(SkCanvas* canvas) = 0;
 
   // Set the memory limit policy of this compositor.
   virtual void SetMemoryPolicy(size_t bytes_limit) = 0;
 
   // Should be called by the embedder after the embedder had modified the
   // scroll offset of the root layer (as returned by
   // SynchronousCompositorClient::GetTotalRootLayerScrollOffset).
   virtual void DidChangeRootLayerScrollOffset() = 0;
 
+  // VSync callback from the platform.
+  virtual void OnVSync(base::TimeTicks frame_time, 
+      base::TimeDelta vsync_period) = 0;
+
  protected:
   virtual ~SynchronousCompositor() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_