Store audio device's active state in preference

chromeos/dbus/audio_node.cc

Index: chromeos/dbus/audio_node.cc
diff --git a/chromeos/dbus/audio_node.cc b/chromeos/dbus/audio_node.cc
index c29ffb8753ad94e881388699aaafad9c1a248a67..2eb28700a97e0ed4fd39351eff1599beba17934a 100644
--- a/chromeos/dbus/audio_node.cc
+++ b/chromeos/dbus/audio_node.cc
@@ -19,6 +19,7 @@ AudioNode::AudioNode()
 
 AudioNode::AudioNode(bool is_input,
                      uint64 id,
+                     uint64 stable_device_id,
                      std::string device_name,
                      std::string type,
                      std::string name,
@@ -26,6 +27,7 @@ AudioNode::AudioNode(bool is_input,
                      uint64 plugged_time)
     : is_input(is_input),
       id(id),
+      stable_device_id(stable_device_id),
       device_name(device_name),
       type(type),
       name(name),
@@ -44,6 +46,9 @@ std::string AudioNode::ToString() const {
                       "id = 0x%" PRIx64 " ",
                       id);
   base::StringAppendF(&result,
+                      "stable_device_id = 0x%" PRIx64 " ",
+                      stable_device_id);
+  base::StringAppendF(&result,
                       "device_name = %s ",
                       device_name.c_str());
   base::StringAppendF(&result,