Adding microphone volume support to chrome.

media/audio/audio_io.h

 // Copyright (c) 2011 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 136 matching lines @@
   virtual void Start(AudioInputCallback* callback) = 0;
 
   // Stops recording audio. Effect might not be instantaneous as there could be
   // pending audio callbacks in the queue which will be issued first before
   // recording stops.
   virtual void Stop() = 0;
 
   // Close the stream. This also generates AudioInputCallback::OnClose(). This
   // should be the last call made on this object.
   virtual void Close() = 0;
+
+  // Returns the maximum microphone analog volume.

[henrika (OOO until Aug 14), 2012/02/23 11:50:41]

Perhaps add a comment about return value <=> error?

[no longer working on chromium, 2012/02/24 09:27:48]

Done.

+  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;
 };
 
 #endif  // MEDIA_AUDIO_AUDIO_IO_H_