Test and fix for huge bwe drop after alr state.

webrtc/modules/congestion_controller/bitrate_estimator.h

 /*
  *  Copyright (c) 2017 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_MODULES_CONGESTION_CONTROLLER_ACKNOWLEDGE_BITRATE_ESTIMATOR_H_
-#define WEBRTC_MODULES_CONGESTION_CONTROLLER_ACKNOWLEDGE_BITRATE_ESTIMATOR_H_
+#ifndef WEBRTC_MODULES_CONGESTION_CONTROLLER_BITRATE_ESTIMATOR_H_
+#define WEBRTC_MODULES_CONGESTION_CONTROLLER_BITRATE_ESTIMATOR_H_
 
 #include <vector>
 
 #include "webrtc/base/optional.h"
 
 namespace webrtc {
 
-struct PacketFeedback;
-
 // Computes a bayesian estimate of the throughput given acks containing
 // the arrival time and payload size. Samples which are far from the current
 // estimate or are based on few packets are given a smaller weight, as they
 // are considered to be more likely to have been caused by, e.g., delay spikes
 // unrelated to congestion.
-class AcknowledgedBitrateEstimator {
+class BitrateEstimator {
  public:
-  AcknowledgedBitrateEstimator();
+  BitrateEstimator();
+  virtual ~BitrateEstimator();
+  virtual void Update(int64_t now_ms, int bytes);
 
-  void IncomingPacketFeedbackVector(
-      const std::vector<PacketFeedback>& packet_feedback_vector);
-  rtc::Optional<uint32_t> bitrate_bps() const;
+  virtual rtc::Optional<uint32_t> bitrate_bps() const;
 
  private:
-  void Update(int64_t now_ms, int bytes);
   float UpdateWindow(int64_t now_ms, int bytes, int rate_window_ms);
-
   int sum_;
   int64_t current_win_ms_;
   int64_t prev_time_ms_;
   float bitrate_estimate_;
   float bitrate_estimate_var_;
 };
 
 }  // namespace webrtc
 
-#endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_ACKNOWLEDGE_BITRATE_ESTIMATOR_H_
+#endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_BITRATE_ESTIMATOR_H_