Change audio render thread checking to use new AudioRendererSink::BelongsToRendererThread()

media/audio/null_audio_sink.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_AUDIO_NULL_AUDIO_SINK_H_
 #define MEDIA_AUDIO_NULL_AUDIO_SINK_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 16 matching lines @@
 
   // AudioRendererSink implementation.
   void Initialize(const AudioParameters& params,
                   RenderCallback* callback) override;
   void Start() override;
   void Stop() override;
   void Pause() override;
   void Play() override;
   bool SetVolume(double volume) override;
   OutputDeviceInfo GetOutputDeviceInfo() override;
+  bool BelongsToRenderingThread() override;
   void SwitchOutputDevice(const std::string& device_id,
                           const url::Origin& security_origin,
                           const OutputDeviceStatusCB& callback) override;
 
   // Enables audio frame hashing.  Must be called prior to Initialize().
   void StartAudioHashForTesting();
 
   // Returns the hash of all audio frames seen since construction.
   std::string GetAudioHashForTesting();
 
@@ skipping 15 matching lines @@
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   std::unique_ptr<FakeAudioWorker> fake_worker_;
   std::unique_ptr<AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(NullAudioSink);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_NULL_AUDIO_SINK_H_