Calculate the signal level on the media stream local audio track

content/renderer/media/webrtc_local_audio_track.h

Index: content/renderer/media/webrtc_local_audio_track.h
diff --git a/content/renderer/media/webrtc_local_audio_track.h b/content/renderer/media/webrtc_local_audio_track.h
index 70ae7bbccb3dc15f82d6a277971ef0205581ed4f..af7151b97d0d021fb1f8adbc31410322e51fd8c1 100644
--- a/content/renderer/media/webrtc_local_audio_track.h
+++ b/content/renderer/media/webrtc_local_audio_track.h
@@ -18,6 +18,7 @@
 
 namespace content {
 
+class MediaStreamAudioLevelCalculator;
 class MediaStreamAudioSink;
 class MediaStreamAudioSinkOwner;
 class MediaStreamAudioTrackSink;
@@ -116,6 +117,10 @@ class CONTENT_EXPORT WebRtcLocalAudioTrack
   // WebAudio.
   scoped_ptr<WebRtcLocalAudioSourceProvider> source_provider_;
 
+  // Used to calculate the signal level that shows in the UI.
+  // Accessed on only the audio thread.
+  scoped_ptr<MediaStreamAudioLevelCalculator> level_calculator_;

[tommi (sloooow) - chröme, 2014/02/27 08:39:43]

what about just making this a non pointer?
MediaStreamAudioLevelCalculator level_calculator_;

[no longer working on chromium, 2014/02/28 08:16:25]

No, we can't. In WebRtcAudioCapturer, we will re-create a new source if the
format changes, that means we will have new audio thread. And
MediaStreamAudioLevelCalculator is a non-thread safe object, so we need to
create a new object each time the format changes.

+
   DISALLOW_COPY_AND_ASSIGN(WebRtcLocalAudioTrack);
 };