Store audio device's active state in preference

chromeos/audio/audio_device.cc

Index: chromeos/audio/audio_device.cc
diff --git a/chromeos/audio/audio_device.cc b/chromeos/audio/audio_device.cc
index 27109ed9988803a007d6992b3fbde5bbf4b8d591..1ea9fefee5150bd7ea395d7c5d20d8a48d37e5c7 100644
--- a/chromeos/audio/audio_device.cc
+++ b/chromeos/audio/audio_device.cc
@@ -107,6 +107,7 @@ AudioDeviceType AudioDevice::GetAudioType(
 AudioDevice::AudioDevice()
     : is_input(false),
       id(0),
+      stable_device_id(0),
       display_name(""),
       type(AUDIO_TYPE_OTHER),
       priority(0),
@@ -117,6 +118,7 @@ AudioDevice::AudioDevice()
 AudioDevice::AudioDevice(const AudioNode& node) {
   is_input = node.is_input;
   id = node.id;
+  stable_device_id = node.stable_device_id;
   type = GetAudioType(node.type);
   if (!node.name.empty() && node.name != "(default)")
     display_name = node.name;