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

talk/app/webrtc/mediacontroller.cc

Index: talk/app/webrtc/mediacontroller.cc
diff --git a/talk/app/webrtc/mediacontroller.cc b/talk/app/webrtc/mediacontroller.cc
index 28b007e15b787e94fe92aa9ad385a1165350f139..f38196788ea956cc5da043d1f34024f39de1f8c1 100644
--- a/talk/app/webrtc/mediacontroller.cc
+++ b/talk/app/webrtc/mediacontroller.cc
@@ -56,6 +56,10 @@ class MediaController : public webrtc::MediaControllerInterface {
     return call_.get();
   }
 
+  void OnPacketSent(const webrtc::SentPacket& sent_packet) override {
+    call_->OnPacketSent(sent_packet);
+  }
+
  private:
   void Construct_w(webrtc::VoiceEngine* voice_engine)  {
     RTC_DCHECK(worker_thread_->IsCurrent());