Address comments from code review 1505253004

talk/media/base/mediachannel.h

Index: talk/media/base/mediachannel.h
diff --git a/talk/media/base/mediachannel.h b/talk/media/base/mediachannel.h
index 44b9d4fdc5b1c090af7356818cd1eb25dc85d621..0a59019256e5541295f52bc5e8ec35225d725272 100644
--- a/talk/media/base/mediachannel.h
+++ b/talk/media/base/mediachannel.h
@@ -31,7 +31,6 @@
 #include <string>
 #include <vector>
 
-#include "talk/media/base/audiorenderer.h"
 #include "talk/media/base/codec.h"
 #include "talk/media/base/constants.h"
 #include "talk/media/base/streamparams.h"
@@ -58,11 +57,12 @@ class AudioSinkInterface;
 
 namespace cricket {
 
-struct RtpHeader;
+class AudioRenderer;
 class ScreencastId;
-struct VideoFormat;
 class VideoCapturer;
 class VideoRenderer;
+struct RtpHeader;
+struct VideoFormat;
 
 const int kMinRtpHeaderExtensionId = 1;
 const int kMaxRtpHeaderExtensionId = 255;