Begin adding support for tab mirroring via the MediaStream audio/video capturing

content/renderer/media/media_stream_dispatcher.h

Index: content/renderer/media/media_stream_dispatcher.h
diff --git a/content/renderer/media/media_stream_dispatcher.h b/content/renderer/media/media_stream_dispatcher.h
index 549807eb6f9704645807f5030d4b3294e2d31970..9f06885f069b03a11bfe7d8650b34009e2f0e1c8 100644
--- a/content/renderer/media/media_stream_dispatcher.h
+++ b/content/renderer/media/media_stream_dispatcher.h
@@ -152,8 +152,7 @@ class CONTENT_EXPORT MediaStreamDispatcher
   typedef std::map<std::string, Stream> LabelStreamMap;
   LabelStreamMap label_stream_map_;
 
-  EnumerationState audio_enumeration_state_;
-  EnumerationState video_enumeration_state_;
+  EnumerationState enumeration_state_[content::NUM_MEDIA_TYPES];
 
   // List of calls made to GenerateStream that has not yet completed.
   typedef std::list<Request> RequestList;