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

webrtc/modules/congestion_controller/delay_based_bwe.h

 /*
  *  Copyright (c) 2016 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 62 matching lines @@
     int sum_;
     int64_t current_win_ms_;
     int64_t prev_time_ms_;
     float bitrate_estimate_;
     float bitrate_estimate_var_;
     RateStatistics old_estimator_;
     const bool in_experiment_;
   };
 
   Result IncomingPacketInfo(const PacketInfo& info);
+  Result OnLongFeedbackDelay(int64_t arrival_time_ms);
   // Updates the current remote rate estimate and returns true if a valid
   // estimate exists.
   bool UpdateEstimate(int64_t packet_arrival_time_ms,
                       int64_t now_ms,
                       rtc::Optional<uint32_t> acked_bitrate_bps,
                       uint32_t* target_bitrate_bps);
   const bool in_trendline_experiment_;
   const bool in_median_slope_experiment_;
 
   rtc::ThreadChecker network_thread_;
   Clock* const clock_;
   std::unique_ptr<InterArrival> inter_arrival_;
   std::unique_ptr<OveruseEstimator> kalman_estimator_;
   std::unique_ptr<TrendlineEstimator> trendline_estimator_;
   std::unique_ptr<MedianSlopeEstimator> median_slope_estimator_;
   OveruseDetector detector_;
   BitrateEstimator receiver_incoming_bitrate_;
   int64_t last_update_ms_;
   int64_t last_seen_packet_ms_;
   bool uma_recorded_;
   AimdRateControl rate_control_;
   ProbeBitrateEstimator probe_bitrate_estimator_;
   size_t trendline_window_size_;
   double trendline_smoothing_coeff_;
   double trendline_threshold_gain_;
   ProbingIntervalEstimator probing_interval_estimator_;
   size_t median_slope_window_size_;
   double median_slope_threshold_gain_;
+  int consecutive_delayed_feedbacks_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(DelayBasedBwe);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_DELAY_BASED_BWE_H_