[Chromecast] Implement new volume control API

chromecast/media/cma/backend/alsa/audio_filter_interface.h

Index: chromecast/media/cma/backend/alsa/audio_filter_interface.h
diff --git a/chromecast/media/cma/backend/alsa/audio_filter_interface.h b/chromecast/media/cma/backend/alsa/audio_filter_interface.h
index afcb4d59dc4626a56f2483a226acafceb9aaa313..a4e6ddf0359b3a3b14ff37fed7469197d8cf90e7 100644
--- a/chromecast/media/cma/backend/alsa/audio_filter_interface.h
+++ b/chromecast/media/cma/backend/alsa/audio_filter_interface.h
@@ -19,7 +19,7 @@ class AudioFilterInterface {
                                       ::media::SampleFormat sample_format) = 0;
 
   // Process data frames. Must be interleaved. |data| will be overwritten.
-  virtual bool ProcessInterleaved(uint8_t* data, int frames) = 0;
+  virtual bool ProcessInterleaved(uint8_t* data, int frames, float volume) = 0;
 };
 
 }  // namespace media