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

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 9c9e8c4b294f6d060e8c35a3d38b79c456c52fa3..64cc80fd58541a2e4f8daf6cde6d6eb77acd244c 100644
--- a/talk/media/base/mediachannel.h
+++ b/talk/media/base/mediachannel.h
@@ -549,6 +549,7 @@ class MediaChannel : public sigslot::has_slots<> {
   // Called when a RTCP packet is received.
   virtual void OnRtcpReceived(rtc::Buffer* packet,
                               const rtc::PacketTime& packet_time) = 0;
+  virtual void OnPacketSent(const rtc::SentPacket& packet_sent) = 0;

[pthatcher1, 2015/09/25 23:24:57]

Can you just make this default to {}, so we don't have to define a method in all
these data channels where it doesn't make sense?

[stefan-webrtc, 2015/09/28 12:10:49]

Great suggestion. :)

   // Called when the socket's ability to send has changed.
   virtual void OnReadyToSend(bool ready) = 0;
   // Creates a new outgoing media stream with SSRCs and CNAME as described