Store audio device's active state in preference

chromeos/chromeos_pref_names.cc

Index: chromeos/chromeos_pref_names.cc
diff --git a/chromeos/chromeos_pref_names.cc b/chromeos/chromeos_pref_names.cc
index e4c69fa2502be63357acf2fd2311f5a460aac6d4..baafa835384b757f5a33e87cec5aa919998f5522 100644
--- a/chromeos/chromeos_pref_names.cc
+++ b/chromeos/chromeos_pref_names.cc
@@ -33,6 +33,10 @@ const char kAudioOutputAllowed[] = "hardware.audio_output_enabled";
 // |kAudioDevicesVolumePercent| setting.
 const char kAudioVolumePercent[] = "settings.audio.volume_percent";
 
+// An integer pref storing the latest state of an audio device in Chrome OS UI.

[Daniel Erat, 2016/01/07 17:31:12]

this isn't correct, is it? it looks like you're registering this as a dictionary
pref, not an integer.

+// Different state values indicate whether or not a device has been selected
+// as the active one for audio I/O, or it's a new plugged device.

[Daniel Erat, 2016/01/07 17:31:12]

if the different values are stored in an enum, please include the enum's name
here.

+const char kAudioDevicesState[] = "settings.audio.device_state";
 }  // namespace prefs
 }  // namespace chromeos