Detect AudioInputStream muting and propagate to MediaStreamAudioSource.

content/renderer/media/local_media_stream_audio_source.cc

 // Copyright 2016 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.
 
 #include "content/renderer/media/local_media_stream_audio_source.h"
 
 #include "content/common/media/media_stream_options.h"
 #include "content/renderer/media/audio_device_factory.h"
 #include "content/renderer/media/webrtc_logging.h"
 #include "content/renderer/render_frame_impl.h"
@@ skipping 92 matching lines @@
       *audio_bus,
       base::TimeTicks::Now() -
       base::TimeDelta::FromMilliseconds(audio_delay_milliseconds));
 }
 
 void LocalMediaStreamAudioSource::OnCaptureError(const std::string& why) {
   WebRtcLogMessage("LocalMediaStreamAudioSource::OnCaptureError: " + why);
   StopSourceOnError(why);
 }
 
+void LocalMediaStreamAudioSource::OnCaptureMuted(bool is_muted) {
+  SetMutedState(is_muted);
+}
+
 }  // namespace content