Create a new QUIC BBR ack aggregation patch which allows extra CWND only when bytes in flight has g…

net/quic/core/congestion_control/bbr_sender.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // BBR (Bottleneck Bandwidth and RTT) congestion control algorithm.
 
 #ifndef NET_QUIC_CORE_CONGESTION_CONTROL_BBR_SENDER_H_
 #define NET_QUIC_CORE_CONGESTION_CONTROL_BBR_SENDER_H_
 
 #include <cstdint>
@@ skipping 231 matching lines @@
   // round-trips.
   MaxBandwidthFilter max_bandwidth_;
 
   // Tracks the maximum number of bytes acked faster than the sending rate.
   MaxAckHeightFilter max_ack_height_;
 
   // The time this aggregation started and the number of bytes acked during it.
   QuicTime aggregation_epoch_start_time_;
   QuicByteCount aggregation_epoch_bytes_;
 
+  // The number of bytes acknowledged since the last time bytes in flight
+  // dropped below the target window.
+  QuicByteCount bytes_acked_since_queue_drained_;
+
   // Minimum RTT estimate.  Automatically expires within 10 seconds (and
   // triggers PROBE_RTT mode) if no new value is sampled during that period.
   QuicTime::Delta min_rtt_;
   // The time at which the current value of |min_rtt_| was assigned.
   QuicTime min_rtt_timestamp_;
 
   // The maximum allowed number of bytes in flight.
   QuicByteCount congestion_window_;
 
   // The initial value of the |congestion_window_|.
@@ skipping 80 matching lines @@
 
 QUIC_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
                                              const BbrSender::Mode& mode);
 QUIC_EXPORT_PRIVATE std::ostream& operator<<(
     std::ostream& os,
     const BbrSender::DebugState& state);
 
 }  // namespace net
 
 #endif  // NET_QUIC_CORE_CONGESTION_CONTROL_BBR_SENDER_H_