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

chromeos/audio/audio_devices_pref_handler_impl.h

Index: chromeos/audio/audio_devices_pref_handler_impl.h
diff --git a/chromeos/audio/audio_devices_pref_handler_impl.h b/chromeos/audio/audio_devices_pref_handler_impl.h
index 7e30e591cabdba8ff65bf043ddbcd03c2e6efcd0..f9090a593acd8f203869b6272c46c9fd4ceebe90 100644
--- a/chromeos/audio/audio_devices_pref_handler_impl.h
+++ b/chromeos/audio/audio_devices_pref_handler_impl.h
@@ -35,9 +35,12 @@ class CHROMEOS_EXPORT AudioDevicesPrefHandlerImpl
   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;