Add the last_sent_packet_id to the candidate pair change signal

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 2006391463b276e10d83df436ce1541bc00b82db..667b2c82b2865f6ae622f66652f86f3afe1577a4 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -638,9 +638,11 @@ void DtlsTransportChannelWrapper::OnRouteChange(
 
 void DtlsTransportChannelWrapper::OnSelectedCandidatePairChanged(
     TransportChannel* channel,
-    CandidatePairInterface* selected_candidate_pair) {
+    CandidatePairInterface* selected_candidate_pair,
+    int last_sent_packet_id) {
   ASSERT(channel == channel_);
-  SignalSelectedCandidatePairChanged(this, selected_candidate_pair);
+  SignalSelectedCandidatePairChanged(this, selected_candidate_pair,
+                                     last_sent_packet_id);
 }
 
 void DtlsTransportChannelWrapper::OnConnectionRemoved(