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

content/renderer/media/webrtc_audio_device_impl.h

Index: content/renderer/media/webrtc_audio_device_impl.h
diff --git a/content/renderer/media/webrtc_audio_device_impl.h b/content/renderer/media/webrtc_audio_device_impl.h
index 6af4a86935616b627b7874177142486df6638100..1e3f05f1a6473f7d7427b6e2033f897cb72a9c34 100644
--- a/content/renderer/media/webrtc_audio_device_impl.h
+++ b/content/renderer/media/webrtc_audio_device_impl.h
@@ -219,7 +219,7 @@ class WebRtcPlayoutDataSource {
   class Sink {
    public:
     // Callback to get the playout data.
-    // Called on the render audio thread.
+    // Called on the audio render thread.
     virtual void OnPlayoutData(media::AudioBus* audio_bus,
                                int sample_rate,
                                int audio_delay_milliseconds) = 0;
@@ -228,6 +228,11 @@ class WebRtcPlayoutDataSource {
     // Called on the main render thread.
     virtual void OnPlayoutDataSourceChanged() = 0;
 
+    // Called to notify that the audio render thread has changed, and
+    // OnPlayoutData() will from now on be called on the new thread.
+    // Called on the new audio render thread.
+    virtual void OnRenderThreadChanged() = 0;
+
    protected:
     virtual ~Sink() {}
   };