Avoid hitting the thread check when WebRtcAudioRenderer is going away.

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 7354002dcaa6c79129ecf24e5517b2917bc9e14a..b885d0d9fcfb30cc21d6dcb195168e46081f4d79 100644
--- a/content/renderer/media/webrtc_audio_device_impl.h
+++ b/content/renderer/media/webrtc_audio_device_impl.h
@@ -242,6 +242,10 @@ class WebRtcPlayoutDataSource {
     virtual void OnPlayoutData(media::AudioBus* audio_bus,
                                int sample_rate,
                                int audio_delay_milliseconds) = 0;
+
+    // Callback to notify the sink that the source has changed.
+    virtual void OnPlayoutDataSourceChanged() = 0;

[tommi (sloooow) - chröme, 2014/03/04 20:48:39]

also document thread semantics

[no longer working on chromium, 2014/03/05 13:01:04]

Done.

+
    protected:
     virtual ~Sink() {}
   };