Chromecast: mitigate threading issue between AvPipeline/MediaKeys.

chromecast/media/cma/pipeline/av_pipeline_impl.h

 // Copyright 2014 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 CHROMECAST_MEDIA_CMA_BASE_AV_PIPELINE_IMPL_H_
 #define CHROMECAST_MEDIA_CMA_BASE_AV_PIPELINE_IMPL_H_
 
 #include <list>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "chromecast/media/cma/backend/media_component_device.h"
 #include "chromecast/media/cma/pipeline/av_pipeline_client.h"
 
 namespace media {
 class AudioDecoderConfig;
 class VideoDecoderConfig;
 }
 
 namespace chromecast {
@@ skipping 126 matching lines @@
 
   // Indicate if there is a frame being pushed to the audio device.
   bool pending_push_;
 
   // The media time is retrieved at regular intervals.
   // Indicate whether time update is enabled.
   bool enable_time_update_;
   bool pending_time_update_task_;
 
   // Decryption keys, if available.
+  base::Lock media_keys_lock_;
   BrowserCdmCast* media_keys_;
   int media_keys_callback_id_;
 
   base::WeakPtr<AvPipelineImpl> weak_this_;
   base::WeakPtrFactory<AvPipelineImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AvPipelineImpl);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BASE_AV_PIPELINE_IMPL_H_