Prepare MediaDrmBridge to work with MediaCodecPlayer

media/cdm/player_tracker_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 MEDIA_CDM_PLAYER_TRACKER_IMPL_H_
 #define MEDIA_CDM_PLAYER_TRACKER_IMPL_H_
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "media/base/media_export.h"
 #include "media/base/player_tracker.h"
 
 namespace media {
 
 // A common implementation that can be shared by different PlayerTracker
 // implementations. This class is not thread safe and should only be called
 // on one thread.
 class MEDIA_EXPORT PlayerTrackerImpl : public PlayerTracker {
@@ skipping 17 matching lines @@
 
     base::Closure new_key_cb;
     base::Closure cdm_unset_cb;
   };
 
   int next_registration_id_;
   std::map<int, PlayerCallbacks> player_callbacks_map_;
 
   base::ThreadChecker thread_checker_;
 
+  // Unable to post RegisterPlayer() to another thread since it returns the new
+  // id.
+  base::Lock lock_;
+
   DISALLOW_COPY_AND_ASSIGN(PlayerTrackerImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CDM_PLAYER_TRACKER_IMPL_H_