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

webrtc/modules/congestion_controller/delay_based_bwe.h

Index: webrtc/modules/congestion_controller/delay_based_bwe.h
diff --git a/webrtc/modules/congestion_controller/delay_based_bwe.h b/webrtc/modules/congestion_controller/delay_based_bwe.h
index 6342d05927c40a69b6a56393ca524664c536d283..d1a9676d59d43a2c4f1f8b8818e4362b4453e1bf 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.h
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.h
@@ -80,6 +80,7 @@ class DelayBasedBwe {
   };
 
   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,
@@ -108,6 +109,7 @@ class DelayBasedBwe {
   ProbingIntervalEstimator probing_interval_estimator_;
   size_t median_slope_window_size_;
   double median_slope_threshold_gain_;
+  int consecutive_delayed_feedbacks_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(DelayBasedBwe);
 };