Send vsync timebase updates to the browser compositor

content/common/gpu/image_transport_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_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_
 #define CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_
 
 #if defined(ENABLE_GPU)
 
 #include <vector>
@@ skipping 96 matching lines @@
   // like size and surface id. The helper fills in the rest.
   void SendAcceleratedSurfaceNew(
       GpuHostMsg_AcceleratedSurfaceNew_Params params);
   void SendAcceleratedSurfaceBuffersSwapped(
       GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params);
   void SendAcceleratedSurfacePostSubBuffer(
       GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params params);
   void SendAcceleratedSurfaceRelease(
       GpuHostMsg_AcceleratedSurfaceRelease_Params params);
   void SendResizeView(const gfx::Size& size);
+  void SendUpdateVSyncParameters(
+      base::TimeTicks timebase, base::TimeDelta interval);
 
   // Whether or not we should execute more commands.
   void SetScheduled(bool is_scheduled);
 
   void DeferToFence(base::Closure task);
 
   void SetPreemptByCounter(
       scoped_refptr<gpu::RefCountedCounter> preempt_by_counter);
 
   // Make the surface's context current.
@@ skipping 52 matching lines @@
   // ImageTransportSurface implementation.
   virtual void OnBufferPresented(bool presented,
                                  uint32 sync_point) OVERRIDE;
   virtual void OnResizeViewACK() OVERRIDE;
   virtual void OnResize(gfx::Size size) OVERRIDE;
   virtual gfx::Size GetSize() OVERRIDE;
 
  protected:
   virtual ~PassThroughImageTransportSurface();
 
+  // If updated vsync parameters can be determined, send this information to
+  // the browser.
+  virtual void SendVSyncUpdateIfAvailable();
+
  private:
   scoped_ptr<ImageTransportHelper> helper_;
   gfx::Size new_size_;
   bool transport_;
   bool did_set_swap_interval_;
 
   DISALLOW_COPY_AND_ASSIGN(PassThroughImageTransportSurface);
 };
 
 }  // namespace content
 
 #endif  // defined(ENABLE_GPU)
 
 #endif  // CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_