Adding some features to proxy.h, and restructuring the macros.

webrtc/api/mediastreamproxy.h

Index: webrtc/api/mediastreamproxy.h
diff --git a/webrtc/api/mediastreamproxy.h b/webrtc/api/mediastreamproxy.h
index 06f8eb3b2cf8fcd9e144300f9ca1203a59e1ddae..4253a093c4b43b892b0cf530b8ece813ba7d36d2 100644
--- a/webrtc/api/mediastreamproxy.h
+++ b/webrtc/api/mediastreamproxy.h
@@ -17,20 +17,23 @@
 namespace webrtc {
 
 BEGIN_SIGNALING_PROXY_MAP(MediaStream)
+  PROXY_SIGNALING_THREAD_DESTRUCTOR()
   PROXY_CONSTMETHOD0(std::string, label)
   PROXY_METHOD0(AudioTrackVector, GetAudioTracks)
   PROXY_METHOD0(VideoTrackVector, GetVideoTracks)
   PROXY_METHOD1(rtc::scoped_refptr<AudioTrackInterface>,
-                FindAudioTrack, const std::string&)
+                FindAudioTrack,
+                const std::string&)
   PROXY_METHOD1(rtc::scoped_refptr<VideoTrackInterface>,
-                FindVideoTrack, const std::string&)
+                FindVideoTrack,
+                const std::string&)
   PROXY_METHOD1(bool, AddTrack, AudioTrackInterface*)
   PROXY_METHOD1(bool, AddTrack, VideoTrackInterface*)
   PROXY_METHOD1(bool, RemoveTrack, AudioTrackInterface*)
   PROXY_METHOD1(bool, RemoveTrack, VideoTrackInterface*)
   PROXY_METHOD1(void, RegisterObserver, ObserverInterface*)
   PROXY_METHOD1(void, UnregisterObserver, ObserverInterface*)
-END_SIGNALING_PROXY()
+END_PROXY_MAP()
 
 }  // namespace webrtc