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

webrtc/p2p/base/dtlstransportchannel.h

Index: webrtc/p2p/base/dtlstransportchannel.h
diff --git a/webrtc/p2p/base/dtlstransportchannel.h b/webrtc/p2p/base/dtlstransportchannel.h
index 9a2ccdee992198eb99593ed34d7fac70594e2a03..fd6bc2498deab7b5cacb4806a71c7d312e0b4250 100644
--- a/webrtc/p2p/base/dtlstransportchannel.h
+++ b/webrtc/p2p/base/dtlstransportchannel.h
@@ -209,6 +209,8 @@ class DtlsTransportChannelWrapper : public TransportChannelImpl {
   void OnWritableState(TransportChannel* channel);
   void OnReadPacket(TransportChannel* channel, const char* data, size_t size,
                     const rtc::PacketTime& packet_time, int flags);
+  void OnSentPacket(TransportChannel* channel,
+                    const rtc::SentPacket& sent_packet);
   void OnReadyToSend(TransportChannel* channel);
   void OnReceivingState(TransportChannel* channel);
   void OnDtlsEvent(rtc::StreamInterface* stream_, int sig, int err);