Reduce the BWE with 50% when feedback is received too late.

webrtc/modules/congestion_controller/congestion_controller.cc

 /*
  *  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 192 matching lines @@
   bitrate_controller_->SetBitrates(start_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);
 
   probe_controller_->SetBitrates(min_bitrate_bps, start_bitrate_bps,
                                  max_bitrate_bps);
   max_bitrate_bps_ = max_bitrate_bps;
 
   remote_bitrate_estimator_.SetMinBitrate(min_bitrate_bps);
   min_bitrate_bps_ = min_bitrate_bps;
-  transport_feedback_adapter_.SetStartBitrate(start_bitrate_bps);
+  if (start_bitrate_bps > 0)
+    transport_feedback_adapter_.SetStartBitrate(start_bitrate_bps);
   transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps_);
   MaybeTriggerOnNetworkChanged();
 }
 
 void CongestionController::ResetBweAndBitrates(int bitrate_bps,
                                                int min_bitrate_bps,
                                                int max_bitrate_bps) {
   ClampBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   // TODO(honghaiz): Recreate this object once the bitrate controller is
   // no longer exposed outside CongestionController.
@@ skipping 145 matching lines @@
 bool CongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }
 
 bool CongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&critsect_);
   return network_state_ == kNetworkDown;
 }
 
 }  // namespace webrtc