Reset the BWE when the network changes

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 bbf3e5c484b0302672ea889665ec4ec0ac285134..cb77cde92c81b7c89cf2e1b8175227276bf308bc 100644
--- a/webrtc/p2p/base/dtlstransportchannel.cc
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -119,6 +119,8 @@ DtlsTransportChannelWrapper::DtlsTransportChannelWrapper(
       &DtlsTransportChannelWrapper::OnRoleConflict);
   channel_->SignalRouteChange.connect(this,
       &DtlsTransportChannelWrapper::OnRouteChange);
+  channel_->SignalBestConnectionChanged.connect(
+      this, &DtlsTransportChannelWrapper::OnBestConnectionChanged);
   channel_->SignalConnectionRemoved.connect(this,
       &DtlsTransportChannelWrapper::OnConnectionRemoved);
   channel_->SignalReceivingState.connect(this,
@@ -634,6 +636,13 @@ void DtlsTransportChannelWrapper::OnRouteChange(
   SignalRouteChange(this, candidate);
 }
 
+void DtlsTransportChannelWrapper::OnBestConnectionChanged(
+    TransportChannel* channel,
+    Connection* best_connection) {
+  ASSERT(channel == channel_);
+  SignalBestConnectionChanged(this, best_connection);
+}
+
 void DtlsTransportChannelWrapper::OnConnectionRemoved(
     TransportChannelImpl* channel) {
   ASSERT(channel == channel_);