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

webrtc/p2p/base/dtlstransportchannel.cc

Index: webrtc/p2p/base/dtlstransportchannel.cc
diff --git a/webrtc/p2p/base/dtlstransportchannel.cc b/webrtc/p2p/base/dtlstransportchannel.cc
index b434d0860e1e73763a89d1fddbc2439d39fd5c4f..70b385bcf8fbe9e4a1a2e7fdbd11a166080a8d5d 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -101,6 +101,8 @@ DtlsTransportChannelWrapper::DtlsTransportChannelWrapper(
       &DtlsTransportChannelWrapper::OnWritableState);
   channel_->SignalReadPacket.connect(this,
       &DtlsTransportChannelWrapper::OnReadPacket);
+  channel_->SignalSentPacket.connect(
+      this, &DtlsTransportChannelWrapper::OnSentPacket);
   channel_->SignalReadyToSend.connect(this,
       &DtlsTransportChannelWrapper::OnReadyToSend);
   channel_->SignalGatheringState.connect(
@@ -511,6 +513,15 @@ void DtlsTransportChannelWrapper::OnReadPacket(
   }
 }
 
+void DtlsTransportChannelWrapper::OnSentPacket(
+    TransportChannel* channel,
+    const rtc::SentPacket& packet_sent) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == channel_);
+
+  SignalSentPacket(this, packet_sent);
+}
+
 void DtlsTransportChannelWrapper::OnReadyToSend(TransportChannel* channel) {
   if (writable()) {
     SignalReadyToSend(this);