Adds Analog Gain Control (AGC) to the WebRTC client.

media/audio/audio_io.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_AUDIO_IO_H_
 #define MEDIA_AUDIO_AUDIO_IO_H_
 
 #include "base/basictypes.h"
 #include "media/audio/audio_buffers_state.h"
 
@@ skipping 104 matching lines @@
 class MEDIA_EXPORT AudioInputStream {
  public:
   class MEDIA_EXPORT AudioInputCallback {
    public:
     virtual ~AudioInputCallback() {}
 
     // Called by the audio recorder when a full packet of audio data is
     // available. This is called from a special audio thread and the
     // implementation should return as soon as possible.
     virtual void OnData(AudioInputStream* stream, const uint8* src,
-                        uint32 size, uint32 hardware_delay_bytes) = 0;
+                        uint32 size, uint32 hardware_delay_bytes,
+                        double volume) = 0;
 
     // The stream is done with this callback, the last call received by this
     // audio sink.
     virtual void OnClose(AudioInputStream* stream) = 0;
 
     // There was an error while recording audio. The audio sink cannot be
     // destroyed yet. No direct action needed by the AudioInputStream, but it
     // is a good place to stop accumulating sound data since is is likely that
     // recording will not continue. |code| is an error code that is platform
     // specific.
@@ skipping 21 matching lines @@
 
   // Returns the maximum microphone analog volume or 0.0 if device does not
   // have volume control.
   virtual double GetMaxVolume() = 0;
 
   // Sets the microphone analog volume, with range [0, max_volume] inclusive.
   virtual void SetVolume(double volume) = 0;
 
   // Returns the microphone analog volume, with range [0, max_volume] inclusive.
   virtual double GetVolume() = 0;
+
+  // Sets the Automatic Gain Control (AGC) state.
+  virtual void SetAutomaticGainControl(bool enabled) = 0;
+
+  // Returns the Automatic Gain Control (AGC) state.
+  virtual bool GetAutomaticGainControl() = 0;
 };
 
 #endif  // MEDIA_AUDIO_AUDIO_IO_H_