Add support for audio input mute detection on all platforms

media/audio/win/audio_low_latency_input_win.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.
 //
 // Implementation of AudioInputStream for Windows using Windows Core Audio
 // WASAPI for low latency capturing.
 //
 // Overview of operation:
 //
 // - An object of WASAPIAudioInputStream is created by the AudioManager
@@ skipping 84 matching lines @@
   virtual ~WASAPIAudioInputStream();
 
   // 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;
 
   bool started() const { return started_; }
 
   // Returns the default hardware audio parameters of the specific device.
   static AudioParameters GetInputStreamParameters(const std::string& device_id);
 
  private:
   // DelegateSimpleThread::Delegate implementation.
   virtual void Run() override;
 
@@ skipping 102 matching lines @@
   // Extra audio bus used for storage of deinterleaved data for the OnData
   // callback.
   scoped_ptr<media::AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(WASAPIAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_WIN_AUDIO_LOW_LATENCY_INPUT_WIN_H_