Use bayesian estimate of acked bitrate.

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 c5be7652324bb7f26c7fbbd5fe5bb21c90684ad2..3e369fcdf13c323e9265b5619a38d6122e41ebf9 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.h
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.h
@@ -11,9 +11,9 @@
 #ifndef WEBRTC_MODULES_CONGESTION_CONTROLLER_DELAY_BASED_BWE_H_
 #define WEBRTC_MODULES_CONGESTION_CONTROLLER_DELAY_BASED_BWE_H_
 
-#include <list>
-#include <map>
+#include <deque>
 #include <memory>
+#include <utility>
 #include <vector>
 
 #include "webrtc/base/checks.h"
@@ -53,11 +53,27 @@ class DelayBasedBwe {
   void SetMinBitrate(int min_bitrate_bps);
 
  private:
+  class RateEstimator {
+   public:
+    RateEstimator();
+    void Update(int64_t now_ms, int bytes);
+    int bitrate_estimate() const;
+
+   private:
+    void UpdateWindow(int64_t now_ms, int bytes);
+    int sum_;
+    int count_;
+    std::deque<std::pair<int64_t, int>> payloads_;
+    float bitrate_estimate_;
+    float bitrate_estimate_std_;
+  };
+
   Result IncomingPacketInfo(const PacketInfo& info);
   // 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,
+                      int acked_bitrate_bps,
                       uint32_t* target_bitrate_bps);
 
   rtc::ThreadChecker network_thread_;
@@ -65,7 +81,7 @@ class DelayBasedBwe {
   std::unique_ptr<InterArrival> inter_arrival_;
   std::unique_ptr<OveruseEstimator> estimator_;
   OveruseDetector detector_;
-  RateStatistics receiver_incoming_bitrate_;
+  RateEstimator receiver_incoming_bitrate_;
   int64_t last_update_ms_;
   int64_t last_seen_packet_ms_;
   bool uma_recorded_;