Add a new rate based sending connection option which uses the pacing rate to keep the bytes_in_flig…

net/quic/congestion_control/tcp_cubic_sender_base.h

 // Copyright (c) 2012 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.
 //
 // TCP cubic send side congestion algorithm, emulates the behavior of TCP cubic.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_TCP_CUBIC_SENDER_BASE_H_
 #define NET_QUIC_CONGESTION_CONTROL_TCP_CUBIC_SENDER_BASE_H_
 
 #include <stdint.h>
@@ skipping 43 matching lines @@
                          const CongestionVector& lost_packets) override;
   bool OnPacketSent(QuicTime sent_time,
                     QuicByteCount bytes_in_flight,
                     QuicPacketNumber packet_number,
                     QuicByteCount bytes,
                     HasRetransmittableData is_retransmittable) override;
   void OnRetransmissionTimeout(bool packets_retransmitted) override;
   void OnConnectionMigration() override;
   QuicTime::Delta TimeUntilSend(QuicTime now,
                                 QuicByteCount bytes_in_flight) const override;
-  QuicBandwidth PacingRate() const override;
+  QuicBandwidth PacingRate(QuicByteCount bytes_in_flight) const override;
   QuicBandwidth BandwidthEstimate() const override;
   QuicTime::Delta RetransmissionDelay() const override;
   bool InSlowStart() const override;
   bool InRecovery() const override;
 
  protected:
   // Called when resuming a previous bandwidth.
   virtual void SetCongestionWindowFromBandwidthAndRtt(QuicBandwidth bandwidth,
                                                       QuicTime::Delta rtt) = 0;
 
@@ skipping 61 matching lines @@
   // Whether to use 4 packets as the actual min, but pace lower.
   bool min4_mode_;
 
   // Whether the last loss event caused us to exit slowstart.
   // Used for stats collection of slowstart_packets_lost
   bool last_cutback_exited_slowstart_;
 
   // When true, exit slow start with large cutback of congestion window.
   bool slow_start_large_reduction_;
 
+  // When true, use rate based sending instead of only sending if there's CWND.
+  bool rate_based_sending_;
+
   // When true, use unity pacing instead of PRR.
   bool no_prr_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TcpCubicSenderBase);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_TCP_CUBIC_SENDER_BASE_H_