Use byte conservation instead of packet conservation in QUIC's Slow Start Large Recovery experiment…

net/quic/congestion_control/tcp_cubic_sender_bytes.cc

 // Copyright (c) 2015 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.
 
 #include "net/quic/congestion_control/tcp_cubic_sender_bytes.h"
 
 #include <algorithm>
 
 #include "net/quic/congestion_control/prr_sender.h"
 #include "net/quic/congestion_control/rtt_stats.h"
@@ skipping 63 matching lines @@
 void TcpCubicSenderBytes::SetMaxCongestionWindow(
     QuicByteCount max_congestion_window) {
   max_congestion_window_ = max_congestion_window;
 }
 
 void TcpCubicSenderBytes::ExitSlowstart() {
   slowstart_threshold_ = congestion_window_;
 }
 
 void TcpCubicSenderBytes::OnPacketLost(QuicPacketNumber packet_number,
+                                       QuicByteCount lost_bytes,
                                        QuicByteCount bytes_in_flight) {
   // TCP NewReno (RFC6582) says that once a loss occurs, any losses in packets
   // already sent should be treated as a single loss event, since it's expected.
   if (packet_number <= largest_sent_at_last_cutback_) {
     if (last_cutback_exited_slowstart_) {
       ++stats_->slowstart_packets_lost;
+      stats_->slowstart_bytes_lost += lost_bytes;
       if (slow_start_large_reduction_) {
-        // Reduce congestion window by 1 MSS for every loss.
+        // Reduce congestion window by lost_bytes for every loss.
         congestion_window_ =
-            max(congestion_window_ - kDefaultTCPMSS, min_congestion_window_);
+            max(congestion_window_ - lost_bytes, min_congestion_window_);
         slowstart_threshold_ = congestion_window_;
       }
     }
     DVLOG(1) << "Ignoring loss for largest_missing:" << packet_number
              << " because it was sent prior to the last CWND cutback.";
     return;
   }
   ++stats_->tcp_loss_events;
   last_cutback_exited_slowstart_ = InSlowStart();
   if (InSlowStart()) {
@@ skipping 94 matching lines @@
   congestion_window_ = initial_tcp_congestion_window_;
   max_congestion_window_ = initial_max_tcp_congestion_window_;
   slowstart_threshold_ = initial_max_tcp_congestion_window_;
 }
 
 CongestionControlType TcpCubicSenderBytes::GetCongestionControlType() const {
   return reno_ ? kRenoBytes : kCubicBytes;
 }
 
 }  // namespace net