[chromecast] Slew stream volume changes in StreamMixerAlsa.

chromecast/media/cma/backend/alsa/cast_media_shlib.cc

Index: chromecast/media/cma/backend/alsa/cast_media_shlib.cc
diff --git a/chromecast/media/cma/backend/alsa/cast_media_shlib.cc b/chromecast/media/cma/backend/alsa/cast_media_shlib.cc
index 4a2d49c3cc49dc6c02e5b216f4a9ec15ebe05e0d..6e2bda62456104c51edd2f0bc31ab0da4743c8ac 100644
--- a/chromecast/media/cma/backend/alsa/cast_media_shlib.cc
+++ b/chromecast/media/cma/backend/alsa/cast_media_shlib.cc
@@ -198,8 +198,9 @@ void CastMediaShlib::RemoveLoopbackAudioObserver(
     LoopbackAudioObserver* observer) {
   StreamMixerAlsa::Get()->RemoveLoopbackAudioObserver(observer);
 }
-void SetPostProcessorConfig(const std::string& name,
-                            const std::string& config) {
+
+void CastMediaShlib::SetPostProcessorConfig(const std::string& name,
+                                            const std::string& config) {
   StreamMixerAlsa::Get()->SetPostProcessorConfig(name, config);
 }