Rework FlushSync to return early if commands have been processed since the last update

content/renderer/command_buffer_proxy.h

 // Copyright (c) 2011 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_COMMAND_BUFFER_PROXY_H_
 #define CONTENT_RENDERER_COMMAND_BUFFER_PROXY_H_
 #pragma once
 
 #if defined(ENABLE_GPU)
 
@@ skipping 31 matching lines @@
   virtual void OnChannelError();
 
   int route_id() const { return route_id_; }
 
   // CommandBuffer implementation:
   virtual bool Initialize(int32 size);
   virtual bool Initialize(base::SharedMemory* buffer, int32 size);
   virtual gpu::Buffer GetRingBuffer();
   virtual State GetState();
   virtual void Flush(int32 put_offset);
-  virtual State FlushSync(int32 put_offset);
+  virtual State FlushSync(int32 put_offset, int32 last_known_get);
   virtual void SetGetOffset(int32 get_offset);
   virtual int32 CreateTransferBuffer(size_t size, int32 id_request);
   virtual int32 RegisterTransferBuffer(base::SharedMemory* shared_memory,
                                        size_t size,
                                        int32 id_request);
   virtual void DestroyTransferBuffer(int32 id);
   virtual gpu::Buffer GetTransferBuffer(int32 handle);
   virtual void SetToken(int32 token);
   virtual void SetParseError(gpu::error::Error error);
   virtual void OnSwapBuffers();
@@ skipping 12 matching lines @@
 
 #if defined(OS_MACOSX)
   virtual void SetWindowSize(const gfx::Size& size);
 #endif
 
   // Get the last state received from the service without synchronizing.
   State GetLastState() {
     return last_state_;
   }
 
-  // Get the state asynchronously. The task is posted when the state is
-  // updated. Takes ownership of the task object.
-  void AsyncGetState(Task* completion_task);
-
-  // Flush the command buffer asynchronously. The task is posted when the flush
-  // completes. Takes ownership of the task object.
-  void AsyncFlush(int32 put_offset, Task* completion_task);
-
  private:
 
   // Send an IPC message over the GPU channel. This is private to fully
   // encapsulate the channel; all callers of this function must explicitly
   // verify that the context has not been lost.
   bool Send(IPC::Message* msg);
 
   // Message handlers:
   void OnUpdateState(const gpu::CommandBuffer::State& state);
   void OnNotifyRepaint();
 
   // As with the service, the client takes ownership of the ring buffer.
   int32 num_entries_;
   scoped_ptr<base::SharedMemory> ring_buffer_;
 
   // Local cache of id to transfer buffer mapping.
   typedef std::map<int32, gpu::Buffer> TransferBufferMap;
   TransferBufferMap transfer_buffers_;
 
   // The last cached state received from the service.
   State last_state_;
 
   IPC::Channel::Sender* channel_;
   int route_id_;
 
-  // Pending asynchronous flush callbacks.
-  typedef std::queue<linked_ptr<Task> > AsyncFlushTaskQueue;
-  AsyncFlushTaskQueue pending_async_flush_tasks_;
-
   scoped_ptr<Task> notify_repaint_task_;
 
   scoped_ptr<Callback0::Type> swap_buffers_callback_;
   scoped_ptr<Callback0::Type> channel_error_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(CommandBufferProxy);
 };
 
 #endif  // ENABLE_GPU
 
 #endif  // CONTENT_RENDERER_COMMAND_BUFFER_PROXY_H_