Send vsync timebase updates to the browser compositor

gpu/ipc/command_buffer_proxy.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 GPU_IPC_COMMAND_BUFFER_PROXY_H_
 #define GPU_IPC_COMMAND_BUFFER_PROXY_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 39 matching lines @@
   // Makes this command buffer invoke a task when a sync point is reached, or
   // the command buffer that inserted that sync point is destroyed.
   virtual bool SignalSyncPoint(uint32 sync_point,
                                const base::Closure& callback) = 0;
 
   // Register a callback to invoke whenever we recieve a new memory allocation.
   virtual void SetMemoryAllocationChangedCallback(
       const base::Callback<void(const GpuMemoryAllocationForRenderer&)>&
           callback) = 0;
 
+  // Register a callback to invoke whenever we receive an updated vsync time.
+  virtual void SetUpdateVSyncTimeCallback(
+    const base::Callback<void(int64)>& callback) = 0;
+
   // Reparent a command buffer. TODO(apatrick): going forward, the notion of
   // the parent / child relationship between command buffers is going away in
   // favor of the notion of surfaces that can be drawn to in one command buffer
   // and bound as a texture in any other.
   virtual bool SetParent(CommandBufferProxy* parent_command_buffer,
                          uint32 parent_texture_id) = 0;
 
   virtual void SetChannelErrorCallback(const base::Closure& callback) = 0;
 
   // Set a task that will be invoked the next time the window becomes invalid
   // and needs to be repainted. Takes ownership of task.
   virtual void SetNotifyRepaintTask(const base::Closure& callback) = 0;
 
   virtual void SetOnConsoleMessageCallback(
       const GpuConsoleMessageCallback& callback) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CommandBufferProxy);
 };
 
 #endif  // GPU_IPC_COMMAND_BUFFER_PROXY_H_