Add support for audio input mute detection on all platforms

media/audio/cras/cras_input.h

 // Copyright (c) 2012 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_CRAS_CRAS_INPUT_H_
 #define MEDIA_AUDIO_CRAS_CRAS_INPUT_H_
 
 #include <cras_client.h>
 
 #include <string>
@@ skipping 22 matching lines @@
   virtual ~CrasInputStream();
 
   // Implementation of AudioInputStream.
   virtual bool Open() override;
   virtual void Start(AudioInputCallback* callback) override;
   virtual void Stop() override;
   virtual void Close() override;
   virtual double GetMaxVolume() override;
   virtual void SetVolume(double volume) override;
   virtual double GetVolume() override;
+  virtual bool IsMuted() override;
 
  private:
   // Handles requests to get samples from the provided buffer.  This will be
   // called by the audio server when it has samples ready.
   static int SamplesReady(cras_client* client,
                           cras_stream_id_t stream_id,
                           uint8* samples,
                           size_t frames,
                           const timespec* sample_ts,
                           void* arg);
@@ skipping 46 matching lines @@
   const CRAS_STREAM_DIRECTION stream_direction_;
 
   scoped_ptr<AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_CRAS_CRAS_INPUT_H_