Reland of "Revert of Update the BWE when the network route changes.

webrtc/modules/congestion_controller/include/congestion_controller.h

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 52 matching lines @@
   CongestionController(Clock* clock,
                        Observer* observer,
                        RemoteBitrateObserver* remote_bitrate_observer,
                        std::unique_ptr<PacketRouter> packet_router,
                        std::unique_ptr<PacedSender> pacer);
   virtual ~CongestionController();
 
   virtual void SetBweBitrates(int min_bitrate_bps,
                               int start_bitrate_bps,
                               int max_bitrate_bps);
+  // Resets both the BWE state and the bitrate estimator. Note the first
+  // argument is the bitrate_bps.
+  virtual void ResetBweAndBitrates(int bitrate_bps,
+                                   int min_bitrate_bps,
+                                   int max_bitrate_bps);
   virtual void SignalNetworkState(NetworkState state);
   virtual BitrateController* GetBitrateController() const;
   virtual RemoteBitrateEstimator* GetRemoteBitrateEstimator(
       bool send_side_bwe);
   virtual int64_t GetPacerQueuingDelayMs() const;
   virtual PacedSender* pacer() { return pacer_.get(); }
   virtual PacketRouter* packet_router() { return packet_router_.get(); }
   virtual TransportFeedbackObserver* GetTransportFeedbackObserver();
 
   // SetAllocatedSendBitrateLimits sets bitrates limits imposed by send codec
@@ skipping 41 matching lines @@
   uint8_t last_reported_fraction_loss_ GUARDED_BY(critsect_);
   int64_t last_reported_rtt_ GUARDED_BY(critsect_);
   NetworkState network_state_ GUARDED_BY(critsect_);
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(CongestionController);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_INCLUDE_CONGESTION_CONTROLLER_H_