Unmute Tab Audio For Desktop Share

media/audio/audio_source_diverter.h

 // Copyright (c) 2013 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.
 
 #ifndef MEDIA_AUDIO_AUDIO_SOURCE_DIVERTER_H_
 #define MEDIA_AUDIO_AUDIO_SOURCE_DIVERTER_H_
 
+#include "media/audio/virtual_audio_sink.h"
 #include "media/base/media_export.h"
 
 // Audio sources may optionally implement AudioSourceDiverter to temporarily
 // divert audio data to an alternate AudioOutputStream.  This allows the audio
 // data to be plumbed to an alternate consumer; for example, a loopback
 // mechanism for audio mirroring.
 
 namespace media {
 
 class AudioOutputStream;
 class AudioParameters;
 
 class MEDIA_EXPORT AudioSourceDiverter {
 public:
   // Returns the audio parameters of the divertable audio data.
   virtual const AudioParameters& GetAudioParameters() = 0;
 
   // Start providing audio data to the given |to_stream|, which is in an
   // unopened state.  |to_stream| remains under the control of the
   // AudioSourceDiverter.
   virtual void StartDiverting(AudioOutputStream* to_stream) = 0;
 
   // Stops diverting audio data to the stream.  The AudioSourceDiverter is
   // responsible for making sure the stream is closed, perhaps asynchronously.
   virtual void StopDiverting() = 0;
 
-protected:
+  // Start duplicating the current audio stream, and push the copied data into
+  // |sink|.
+  virtual void StartDuplicating(AudioPushSink* sink) = 0;
+
+  // Stop duplicating for the specified |sink|.

[miu, 2016/05/02 20:06:13]

Please add to this comment that "The AudioSourceDiverter is responsible for
making sure the stream is closed, perhaps asynchronously" (just like the comment
for StopDiverting()).

[qiangchen, 2016/05/03 16:58:23]

Done.

+  virtual void StopDuplicating(AudioPushSink* sink) = 0;
+
+ protected:
   virtual ~AudioSourceDiverter() {}
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_SOURCE_DIVERTER_H_