MuteSource Audio During Full Screen Cast

media/audio/cras/cras_input.h

Index: media/audio/cras/cras_input.h
diff --git a/media/audio/cras/cras_input.h b/media/audio/cras/cras_input.h
index 7dfe215f8896abc4457c15fd064f4d097e37059b..9ab548ec3f5da18f78c4eadc00d96681a06c055c 100644
--- a/media/audio/cras/cras_input.h
+++ b/media/audio/cras/cras_input.h
@@ -111,6 +111,10 @@ class MEDIA_EXPORT CrasInputStream : public AgcAudioStream<AudioInputStream> {
   // True if the stream is a system-wide loopback stream.
   bool is_loopback_;
 
+  // True if we want to mute system audio during capturing.
+  bool mute_system_audio_;
+  bool mute_done_;
+
   std::unique_ptr<AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasInputStream);