Build WebRTC with data channel only.

webrtc/api/mediastreaminterface.h

Index: webrtc/api/mediastreaminterface.h
diff --git a/webrtc/api/mediastreaminterface.h b/webrtc/api/mediastreaminterface.h
index 2acaa000e4898ca1f2c067d1b605b5561d42d406..134a0764ff22b7634435cd11b421c293d9d7d03f 100644
--- a/webrtc/api/mediastreaminterface.h
+++ b/webrtc/api/mediastreaminterface.h
@@ -23,10 +23,13 @@
 #include <vector>
 
 #include "webrtc/api/video/video_frame.h"
+#include "webrtc/base/optional.h"
+#include "webrtc/base/ratetracker.h"

[the sun, 2017/06/12 20:58:40]

How does this belong here? It should be included where it is used.

[Zhi Huang, 2017/06/12 22:18:58]

Many internal projects depend on these header through "mediachannel.h" which we
need to remove to break circular dependenies.  Can we just keep it for now? I'll
 leave a TODO to remove those once the headers are added to downstream apps.

 #include "webrtc/base/refcount.h"
 #include "webrtc/base/scoped_ref_ptr.h"
-#include "webrtc/base/optional.h"
-#include "webrtc/media/base/mediachannel.h"
+#include "webrtc/base/thread.h"

[the sun, 2017/06/12 20:58:40]

likewise

+#include "webrtc/base/timeutils.h"

[the sun, 2017/06/12 20:58:40]

likewise?

+#include "webrtc/media/base/streamparams.h"
 #include "webrtc/media/base/videosinkinterface.h"
 #include "webrtc/media/base/videosourceinterface.h"