Reset the BWE when the network changes

webrtc/p2p/base/p2ptransportchannel.cc

Index: webrtc/p2p/base/p2ptransportchannel.cc
diff --git a/webrtc/p2p/base/p2ptransportchannel.cc b/webrtc/p2p/base/p2ptransportchannel.cc
index e0428d638312b464ce9bc0fc72fdd3f3bfd669b5..428d01bdddc9f762c1b319d52c5d3d2d7a94a1fa 100644
--- a/webrtc/p2p/base/p2ptransportchannel.cc
+++ b/webrtc/p2p/base/p2ptransportchannel.cc
@@ -1165,6 +1165,7 @@ void P2PTransportChannel::SwitchBestConnectionTo(Connection* conn) {
   } else {
     LOG_J(LS_INFO, this) << "No best connection";
   }
+  SignalBestConnectionChanged(this, best_connection_);

[pthatcher1, 2016/03/24 18:46:37]

It would be nice to call this selected_connection_ or even
selected_candidate_pair_.  Could you at least put a TODO?

[honghaiz3, 2016/03/24 22:37:12]

I added a TODO here, will make that change in a separate CL. 

 }
 
 // Warning: UpdateState should eventually be called whenever a connection