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

chrome/browser/chromeos/audio/audio_mixer.h

Index: chrome/browser/chromeos/audio/audio_mixer.h
diff --git a/chrome/browser/chromeos/audio/audio_mixer.h b/chrome/browser/chromeos/audio/audio_mixer.h
index cb9dd67d951fbdb144392b99fdea37a3508220d0..0656aa634a1fb92f677c549078f284df88a9175f 100644
--- a/chrome/browser/chromeos/audio/audio_mixer.h
+++ b/chrome/browser/chromeos/audio/audio_mixer.h
@@ -26,12 +26,33 @@ class AudioMixer {
   // |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);
 };