Reset the BWE when the network changes

webrtc/call.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #ifndef WEBRTC_CALL_H_
@@ skipping 117 matching lines @@
 
   // TODO(pbos): Like BitrateConfig above this is currently per-stream instead
   // of maximum for entire Call. This should be fixed along with the above.
   // Specifying a start bitrate (>0) will currently reset the current bitrate
   // estimate. This is due to how the 'x-google-start-bitrate' flag is currently
   // implemented.
   virtual void SetBitrateConfig(
       const Config::BitrateConfig& bitrate_config) = 0;
   virtual void SignalNetworkState(NetworkState state) = 0;
 
+  virtual void OnNetworkChanged(int local_net_id, int remote_net_id) = 0;

[pthatcher1, 2016/03/16 21:22:03]

To save ourselves trouble later when we want to add more information here (such
as 2g/3g/4g/wifi, or other info), I think it would make sense to pass a struct. 
Perhaps something like:

struct NetworkRoute {
  // False if there is no route currently.
  bool connected;
  // Unset if either there is no route (in which case !connected)
  // or the network ID is unknown.
  Optional<int> local_network_id;
  Optional<int> remote_network_id;
}

And then have could include old and new and save the handler from storing the
old:

OnNetworkRouteChanged(const NetworkRoute& old_route, const NetworkRoute&
new_route);

[honghaiz3, 2016/03/17 03:38:26]

I now just pass the Connection (CandidatePair), which should include every
information we need.

+
   virtual void OnSentPacket(const rtc::SentPacket& sent_packet) = 0;
 
   virtual ~Call() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_CALL_H_