Allow cmdbuffer creation from compositor thread.

content/renderer/gpu/gpu_surface_proxy.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/gpu/gpu_surface_proxy.h"
 #include "ui/gfx/size.h"
 
 GpuSurfaceProxy::GpuSurfaceProxy(
     IPC::Channel::Sender* channel,
     int route_id)
     : channel_(channel),
       route_id_(route_id) {
 }
 
 GpuSurfaceProxy::~GpuSurfaceProxy() {
 }
 
 bool GpuSurfaceProxy::OnMessageReceived(const IPC::Message& message) {
+  if (IsOrphaned())
+      return false;
+
   bool handled = true;
   //IPC_BEGIN_MESSAGE_MAP(GpuSurfaceProxy, message)
   //  IPC_MESSAGE_UNHANDLED(handled = false)
   //IPC_END_MESSAGE_MAP()
   DCHECK(handled);
   return handled;
 }
 
 void GpuSurfaceProxy::OnChannelError() {
   // Prevent any further messages from being sent.
   channel_ = NULL;
 }