Introduce AudioHardwareConfig for renderer side audio device info.

media/audio/audio_output_controller_unittest.cc

Index: media/audio/audio_output_controller_unittest.cc
diff --git a/media/audio/audio_output_controller_unittest.cc b/media/audio/audio_output_controller_unittest.cc
index 746bc45eca4dcfc18bdb4bf619ff8169c8f96ce8..944d6616a1ff36f5bbcd91f4c2872d2f2c324ed2 100644
--- a/media/audio/audio_output_controller_unittest.cc
+++ b/media/audio/audio_output_controller_unittest.cc
@@ -43,7 +43,8 @@ class MockAudioOutputControllerEventHandler
   MOCK_METHOD1(OnPaused, void(AudioOutputController* controller));
   MOCK_METHOD2(OnError, void(AudioOutputController* controller,
                              int error_code));
-
+  MOCK_METHOD3(OnDeviceChange, void(AudioOutputController* controller,
+                                    int new_buffer_size, int new_sample_rate));
  private:
   DISALLOW_COPY_AND_ASSIGN(MockAudioOutputControllerEventHandler);
 };