2 files changed, 4 insertions, 4 deletions
diff --git a/chromeos/audio/audio_devices_pref_handler_impl.cc b/chromeos/audio/audio_devices_pref_handler_impl.cc
index 4e72de6..17b5681 100644
--- a/chromeos/audio/audio_devices_pref_handler_impl.cc
+++ b/chromeos/audio/audio_devices_pref_handler_impl.cc
@@ -187,14 +187,14 @@ void AudioDevicesPrefHandlerImpl::SaveDevicesVolumePref() {
 }
 
 void AudioDevicesPrefHandlerImpl::MigrateDeviceMuteSettings(
-    std::string active_device) {
+    const std::string& active_device) {
   int old_mute = local_state_->GetInteger(prefs::kAudioMute);
   device_mute_settings_->SetInteger(active_device, old_mute);
   SaveDevicesMutePref();
 }
 
 void AudioDevicesPrefHandlerImpl::MigrateDeviceVolumeSettings(
-    std::string active_device) {
+    const std::string& active_device) {
   double old_volume = local_state_->GetDouble(prefs::kAudioVolumePercent);
   device_volume_settings_->SetDouble(active_device, old_volume);
   SaveDevicesVolumePref();
diff --git a/chromeos/audio/audio_devices_pref_handler_impl.h b/chromeos/audio/audio_devices_pref_handler_impl.h
index aeb9f3e..72dc335 100644
--- a/chromeos/audio/audio_devices_pref_handler_impl.h
+++ b/chromeos/audio/audio_devices_pref_handler_impl.h
@@ -64,8 +64,8 @@ class CHROMEOS_EXPORT AudioDevicesPrefHandlerImpl
   // previous global pref value to the new per device pref value for the
   // current active device. If a previous global setting doesn't exist, we'll
   // use default values of mute = off and volume = 75%.
-  void MigrateDeviceMuteSettings(std::string active_device);
-  void MigrateDeviceVolumeSettings(std::string active_device);
+  void MigrateDeviceMuteSettings(const std::string& active_device);
+  void MigrateDeviceVolumeSettings(const std::string& active_device);
 
   // Notifies the AudioPrefObserver for audio policy pref changes.
   void NotifyAudioPolicyChange();