gpu: Add IOSurface backed GpuMemoryBuffer implementation.

content/renderer/render_thread_impl.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 CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 #define CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 486 matching lines @@
   HistogramCustomizer histogram_customizer_;
 
   scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   scoped_ptr<WebRTCIdentityService> webrtc_identity_service_;
 
   scoped_ptr<GamepadSharedMemoryReader> gamepad_shared_memory_reader_;
 
   base::ProcessId renderer_process_id_;
 
+  // TODO(reveman): Allow AllocateGpuMemoryBuffer to be called from
+  // multiple threads. Current allocation mechanism for IOSurface
+  // backed GpuMemoryBuffers prevent this. crbug.com/325045
+  base::ThreadChecker allocate_gpu_memory_buffer_thread_checker_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderThreadImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_THREAD_IMPL_H_