Implement GetAudioOutputDeviceNames for Cras.

media/audio/cras/audio_manager_cras.h

Index: media/audio/cras/audio_manager_cras.h
diff --git a/media/audio/cras/audio_manager_cras.h b/media/audio/cras/audio_manager_cras.h
index 41e1876ac8b0e4ee462a1b10dd595234db26f814..f5caff35af4fbb9e544c96c731ee8a0e247f8949 100644
--- a/media/audio/cras/audio_manager_cras.h
+++ b/media/audio/cras/audio_manager_cras.h
@@ -27,6 +27,8 @@ class MEDIA_EXPORT AudioManagerCras : public AudioManagerBase {
   virtual void ShowAudioInputSettings() OVERRIDE;
   virtual void GetAudioInputDeviceNames(media::AudioDeviceNames* device_names)
       OVERRIDE;
+  virtual void GetAudioOutputDeviceNames(media::AudioDeviceNames* device_names)
+      OVERRIDE;
   virtual AudioParameters GetInputStreamParameters(
       const std::string& device_id) OVERRIDE;
 
@@ -50,9 +52,6 @@ class MEDIA_EXPORT AudioManagerCras : public AudioManagerBase {
       const AudioParameters& input_params) OVERRIDE;
 
  private:
-  // Gets a list of available cras input devices.
-  void GetCrasAudioInputDevices(media::AudioDeviceNames* device_names);
-
   // Called by MakeLinearOutputStream and MakeLowLatencyOutputStream.
   AudioOutputStream* MakeOutputStream(const AudioParameters& params);