Added GPU process "echo" IPC message.

content/renderer/pepper_platform_context_3d_impl.cc

 // 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.
 
 #include "content/renderer/pepper_platform_context_3d_impl.h"
 
 #include "content/renderer/render_thread.h"
 #include "content/renderer/gpu/renderer_gl_context.h"
 #include "content/renderer/gpu/gpu_channel_host.h"
 #include "content/renderer/gpu/command_buffer_proxy.h"
@@ skipping 93 matching lines @@
 
   if (!command_buffer_->SetParent(parent_command_buffer, parent_texture_id_))
     return false;
 
   command_buffer_->SetChannelErrorCallback(callback_factory_.NewCallback(
       &PlatformContext3DImpl::OnContextLost));
 
   return true;
 }
 
-void PlatformContext3DImpl::SetSwapBuffersCallback(Callback0::Type* callback) {
-  DCHECK(command_buffer_);
-  command_buffer_->SetSwapBuffersCallback(callback);
-}
-
 unsigned PlatformContext3DImpl::GetBackingTextureId() {
   DCHECK(command_buffer_);
   return parent_texture_id_;
 }
 
 gpu::CommandBuffer* PlatformContext3DImpl::GetCommandBuffer() {
   return command_buffer_;
 }
 
 int PlatformContext3DImpl::GetCommandBufferRouteId() {
   DCHECK(command_buffer_);
   return command_buffer_->route_id();
 }
 
 void PlatformContext3DImpl::SetContextLostCallback(Callback0::Type* callback) {
   context_lost_callback_.reset(callback);
 }
 
+bool PlatformContext3DImpl::Echo(Task* task) {
+  return command_buffer_->Echo(task);
+}
+
 void PlatformContext3DImpl::OnContextLost() {
   DCHECK(command_buffer_);
 
   if (context_lost_callback_.get())
     context_lost_callback_->Run();
 }
 
 #endif  // ENABLE_GPU