Implement two new policies to control muting the audio I/O.

chrome/browser/chromeos/audio/audio_mixer.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 CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_MIXER_H_
 #define CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_MIXER_H_
 
 #include "base/basictypes.h"
 
 namespace chromeos {
 
 class AudioMixer {
  public:
   AudioMixer() {}
   virtual ~AudioMixer() {}
 
   // Initializes the connection to the device.  This must be called on the UI
   // thread; blocking tasks may take place in the background.  Note that the
   // other methods in this interface can be called before Init().
   virtual void Init() = 0;
 
   // Returns the most-recently-set volume, in the range [0.0, 100.0].
   virtual double GetVolumePercent() = 0;
 
   // Sets the volume, possibly asynchronously.
   // |percent| should be in the range [0.0, 100.0].
   virtual void SetVolumePercent(double percent) = 0;
 
-  // Is the device currently muted?
+  // Is the device currently muted?  If SetMuteLocked has been called with true
+  // this function will not change the mute state until it is unlocked with
+  // another call to SetMuteLocked(false).
   virtual bool IsMuted() = 0;
 
   // Mutes or unmutes the device, possibly asynchronously.
   virtual void SetMuted(bool mute) = 0;
 
+  // Is the device's mute state currently locked?
+  virtual bool IsMuteLocked() = 0;
+
+  // Locks the mute state of the device to muted.  After this is done SetMute
+  // will ignore unmuting requests until SetMuteLocked is called with false.
+  virtual void SetMuteLocked(bool locked) = 0;
+
+  // Is the capture device currently muted?
+  virtual bool IsCaptureMuted() = 0;

[Daniel Erat, 2012/08/28 20:40:51]

It's "mic" in AudioHandler but "capture" here.  Are there any reasons they
shouldn't be consistent?

[pastarmovj, 2012/08/29 08:45:05]

Not really I will change it to capture everywhere to be consistent with Cras.

+
+  // Mutes or unmutes the capture device, possible asynchronously.
+  virtual void SetCaptureMuted(bool mute) = 0;
+
+  // Is the capture device's mute state currently locked?
+  virtual bool IsCaptureMuteLocked() = 0;
+
+  // Locks the capture mute state of the device.
+  virtual void SetCaptureMuteLocked(bool locked) = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(AudioMixer);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_MIXER_H_