Reset the BWE when the network changes

webrtc/pc/channel.cc

Index: webrtc/pc/channel.cc
diff --git a/webrtc/pc/channel.cc b/webrtc/pc/channel.cc
index 2920af53d03887e880fe542b09e8dfa76a67da06..d549eee2019771ddb7023baf9356a362ad963252 100644
--- a/webrtc/pc/channel.cc
+++ b/webrtc/pc/channel.cc
@@ -346,6 +346,8 @@ void BaseChannel::ConnectToTransportChannel(TransportChannel* tc) {
   tc->SignalReadPacket.connect(this, &BaseChannel::OnChannelRead);
   tc->SignalReadyToSend.connect(this, &BaseChannel::OnReadyToSend);
   tc->SignalDtlsState.connect(this, &BaseChannel::OnDtlsState);
+  tc->SignalBestConnectionChanged.connect(
+      this, &BaseChannel::OnBestConnectionChanged);
 }
 
 void BaseChannel::DisconnectFromTransportChannel(TransportChannel* tc) {
@@ -504,6 +506,12 @@ void BaseChannel::OnDtlsState(TransportChannel* channel,
   }
 }
 
+void BaseChannel::OnBestConnectionChanged(TransportChannel* channel,
+                                          Connection* best_connection) {
+  ASSERT(channel == transport_channel_ || channel == rtcp_transport_channel_);
+  media_channel()->OnBestConnectionChanged(best_connection);
+}
+
 void BaseChannel::SetReadyToSend(bool rtcp, bool ready) {
   if (rtcp) {
     rtcp_ready_to_send_ = ready;