Wire up transport sequence number / send time callbacks to webrtc via libjingle.

talk/media/base/constants.h

Index: talk/media/base/constants.h
diff --git a/talk/media/base/constants.h b/talk/media/base/constants.h
index d92cb22514c15659979d356bc1b2699549f8abc4..b6a9e5681f73c6c6ad1489e7a8c0a0ab6cbecacd 100644
--- a/talk/media/base/constants.h
+++ b/talk/media/base/constants.h
@@ -154,6 +154,11 @@ extern const char kRtpVideoRotationHeaderExtension[];
 // We don't support 6 bit CVO. Added here for testing purpose.
 extern const char kRtpVideoRotation6BitsHeaderExtensionForTesting[];
 
+// Header extension for transport sequence number, see url for details:
+// http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions
+extern const int kRtpTransportSequenceNumberHeaderExtensionDefaultId;
+extern const char kRtpTransportSequenceNumberHeaderExtension[];
+
 extern const int kNumDefaultUnsignalledVideoRecvStreams;
 
 extern const char kVp8CodecName[];