Detect AudioInputStream muting and propagate to MediaStreamAudioSource.

content/renderer/media/media_stream_source.h

Index: content/renderer/media/media_stream_source.h
diff --git a/content/renderer/media/media_stream_source.h b/content/renderer/media/media_stream_source.h
index 4ed5f079b8670eec25b66dcfdf161cc056e61eb1..c476ad7c56721a2e3a3ddd0efa5e9187e023202b 100644
--- a/content/renderer/media/media_stream_source.h
+++ b/content/renderer/media/media_stream_source.h
@@ -45,6 +45,9 @@ class CONTENT_EXPORT MediaStreamSource
   // WebMediaStreamSource::readyState to ended.
   void StopSource();
 
+  // Sets the source's state to muted or to live.
+  void SetSourceMuted(bool is_muted);
+
   // Sets device information about a source that has been created by a
   // JavaScript call to GetUserMedia. F.E a camera or microphone.
   void SetDeviceInfo(const StreamDeviceInfo& device_info);