Persist the user's active audio device choice across chromeos session and reboots.

chromeos/audio/audio_devices_pref_handler_impl.h

 // Copyright (c) 2013 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 CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
 #define CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 17 matching lines @@
   explicit AudioDevicesPrefHandlerImpl(PrefService* local_state);
 
   // Overridden from AudioDevicesPrefHandler.
   double GetOutputVolumeValue(const AudioDevice* device) override;
   double GetInputGainValue(const AudioDevice* device) override;
   void SetVolumeGainValue(const AudioDevice& device, double value) override;
 
   bool GetMuteValue(const AudioDevice& device) override;
   void SetMuteValue(const AudioDevice& device, bool mute_on) override;
 
-  AudioDeviceState GetDeviceState(const AudioDevice& device) override;
-  void SetDeviceState(const AudioDevice& device,
-                      AudioDeviceState state) override;
+  void SetDeviceActive(const AudioDevice& device,
+                       bool active,
+                       bool activate_by_user) override;
+  bool GetDeviceActive(const AudioDevice& device,
+                       bool* active,
+                       bool* activate_by_user) override;
 
   bool GetAudioOutputAllowedValue() override;
 
   void AddAudioPrefObserver(AudioPrefObserver* observer) override;
   void RemoveAudioPrefObserver(AudioPrefObserver* observer) override;
 
   // Registers volume and mute preferences.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  protected:
@@ skipping 36 matching lines @@
 
   PrefChangeRegistrar pref_change_registrar_;
   base::ObserverList<AudioPrefObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDevicesPrefHandlerImpl);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_