Read compositor VSync information from platform, when possible

content/renderer/gpu/compositor_output_surface.h

 // Copyright (c) 2012 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_RENDERER_GPU_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_RENDERER_GPU_COMPOSITOR_OUTPUT_SURFACE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
@@ skipping 72 matching lines @@
 
    private:
     friend class base::RefCountedThreadSafe<CompositorOutputSurfaceProxy>;
     ~CompositorOutputSurfaceProxy() {}
     CompositorOutputSurface* output_surface_;
 
     DISALLOW_COPY_AND_ASSIGN(CompositorOutputSurfaceProxy);
   };
 
   void OnMessageReceived(const IPC::Message& message);
-  void OnUpdateVSyncParameters(
-      base::TimeTicks timebase, base::TimeDelta interval);
+  void OnUpdateVSyncParametersFromBrowser(base::TimeTicks timebase,
+                                          base::TimeDelta interval);
 #if defined(OS_ANDROID)
   void OnBeginImplFrame(const cc::BeginFrameArgs& args);
 #endif
   bool Send(IPC::Message* message);
 
   bool use_swap_compositor_frame_message_;
 
   scoped_refptr<IPC::ForwardingMessageFilter> output_surface_filter_;
   scoped_refptr<CompositorOutputSurfaceProxy> output_surface_proxy_;
   scoped_refptr<IPC::SyncMessageFilter> message_sender_;
   int routing_id_;
   bool prefers_smoothness_;
   base::PlatformThreadHandle main_thread_handle_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_COMPOSITOR_OUTPUT_SURFACE_H_