Save/Restore ALSA volume/mute

chrome/browser/chromeos/audio_mixer_alsa.h

Index: chrome/browser/chromeos/audio_mixer_alsa.h
diff --git a/chrome/browser/chromeos/audio_mixer_alsa.h b/chrome/browser/chromeos/audio_mixer_alsa.h
index d365a223dd080a1837c769c28924136d6bdb7715..88b914794626b4d784e3f74b25ec26302506e780 100644
--- a/chrome/browser/chromeos/audio_mixer_alsa.h
+++ b/chrome/browser/chromeos/audio_mixer_alsa.h
@@ -44,6 +44,7 @@ class AudioMixerAlsa : public AudioMixer {
   // and cache mixer handle and mixer elements we'll be using.
   bool InitializeAlsaMixer();
   void FreeAlsaMixer();
+  void DoSetVolumeMute(double volume, bool mute);
 
   // All these internal volume commands must be called with the lock held.
   double DoGetVolumeDb_Locked() const;
@@ -69,6 +70,12 @@ class AudioMixerAlsa : public AudioMixer {
   bool GetElementMuted_Locked(_snd_mixer_elem* elem) const;
   void SetElementMuted_Locked(_snd_mixer_elem* elem, bool mute);
 
+  // Volume and Mute state are persisted in the browser prefs kAudioMute and
+  // kAudioVolume.  These must be run on the UI thread.
+  void RestoreVolumeMute();
+  void SaveVolume(double volume);
+  void SaveMute(bool mute);
+
   // Volume range limits are computed once during InitializeAlsaMixer.
   double min_volume_;
   double max_volume_;