Adds locks for CommandBufferProxyImpl invalidation

media/gpu/ipc/client/gpu_video_decode_accelerator_host.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 MEDIA_GPU_IPC_CLIENT_GPU_VIDEO_DECODE_ACCELERATOR_HOST_H_
 #define MEDIA_GPU_IPC_CLIENT_GPU_VIDEO_DECODE_ACCELERATOR_HOST_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/non_thread_safe.h"
 #include "gpu/ipc/client/command_buffer_proxy_impl.h"
 #include "ipc/ipc_listener.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ui/gfx/geometry/size.h"
 
 struct AcceleratedVideoDecoderHostMsg_PictureReady_Params;
 
 namespace gpu {
 class GpuChannelHost;
@@ skipping 55 matching lines @@
   void OnNotifyError(uint32_t error);
 
   scoped_refptr<gpu::GpuChannelHost> channel_;
 
   // Route ID for the associated decoder in the GPU process.
   int32_t decoder_route_id_;
 
   // The client that will receive callbacks from the decoder.
   Client* client_;
 
+  // Protect |impl_|. |impl_| is used on media thread, but it can be invalidated
+  // on main thread.
+  base::Lock impl_lock_;
+
   // Unowned reference to the gpu::CommandBufferProxyImpl that created us.
   // |this| registers as a DeletionObserver of |impl_|, the so reference is
   // always valid as long as it is not NULL.
   gpu::CommandBufferProxyImpl* impl_;
 
   // Requested dimensions of the buffer, from ProvidePictureBuffers().
   gfx::Size picture_buffer_dimensions_;
 
+  // Task runner for tasks that should run on the thread this class is
+  // constructed.
+  scoped_refptr<base::SingleThreadTaskRunner> media_task_runner_;
+
   // WeakPtr factory for posting tasks back to itself.
   base::WeakPtrFactory<GpuVideoDecodeAcceleratorHost> weak_this_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuVideoDecodeAcceleratorHost);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_GPU_IPC_CLIENT_GPU_VIDEO_DECODE_ACCELERATOR_HOST_H_