Added GPU process "echo" IPC message.

content/renderer/gpu/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_GPU_COMMAND_BUFFER_PROXY_H_
 #define CONTENT_RENDERER_GPU_COMMAND_BUFFER_PROXY_H_
 #pragma once
 
 #if defined(ENABLE_GPU)
 
 #include <map>
 #include <queue>
 
 #include "base/callback_old.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/task.h"
 #include "content/renderer/gpu/gpu_video_decode_accelerator_host.h"
 #include "gpu/command_buffer/common/command_buffer.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_message.h"
 
 namespace base {
 class SharedMemory;
 }
 
 namespace gfx {
@@ skipping 30 matching lines @@
   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 SetContextLostReason(gpu::error::ContextLostReason reason);
-  virtual void OnSwapBuffers();
+
+  // Invoke the task when the channel has been flushed. Takes care of deleting
+  // the task whether the echo succeeds or not.
+  bool Echo(Task* task);
 
   // 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);
 
-  // Set a callback that will be invoked when the SwapBuffers call has been
-  // issued.
-  void SetSwapBuffersCallback(Callback0::Type* callback);
   void SetChannelErrorCallback(Callback0::Type* callback);
 
   // Set a task that will be invoked the next time the window becomes invalid
   // and needs to be repainted. Takes ownership of task.
   void SetNotifyRepaintTask(Task* task);
 
   // Sends an IPC message to create a GpuVideoDecodeAccelerator. Creates and
   // returns a pointer to a GpuVideoDecodeAcceleratorHost.
   // Returns NULL on failure to create the GpuVideoDecodeAcceleratorHost.
   // Note that the GpuVideoDecodeAccelerator may still fail to be created in
   // the GPU process, even if this returns non-NULL. In this case the client is
   // notified of an error later.
   scoped_refptr<GpuVideoDecodeAcceleratorHost> CreateVideoDecoder(
       const std::vector<int32>& configs,
       media::VideoDecodeAccelerator::Client* client);
 
  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();
   void OnDestroyed(gpu::error::ContextLostReason reason);
+  void OnEchoAck();
 
   // 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_;
 
   // Zero or more video decoder hosts owned by this proxy, keyed by their
   // decoder_route_id.
   typedef std::map<int, scoped_refptr<GpuVideoDecodeAcceleratorHost> > Decoders;
   Decoders video_decoder_hosts_;
 
   // The last cached state received from the service.
   State last_state_;
 
   // |*this| is owned by |*channel_| and so is always outlived by it, so using a
   // raw pointer is ok.
   GpuChannelHost* channel_;
   int route_id_;
   unsigned int flush_count_;
 
+  // Tasks to be invoked in echo responses.
+  std::queue<linked_ptr<Task> > echo_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_GPU_COMMAND_BUFFER_PROXY_H_