Land Recent QUIC Changes.

net/quic/congestion_control/tcp_cubic_sender.cc

 // 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.
 
 #include "net/quic/congestion_control/tcp_cubic_sender.h"
 
 #include <algorithm>
 
 #include "base/metrics/histogram.h"
 
@@ skipping 259 matching lines @@
       } else {
         congestion_window_ = std::min(
             max_tcp_congestion_window_,
             cubic_.CongestionWindowAfterAck(congestion_window_, delay_min_));
         DVLOG(1) << "Cubic; congestion window:" << congestion_window_;
       }
     }
   }
 }
 
-void TcpCubicSender::OnRetransmissionTimeout() {
-  cubic_.Reset();
-  congestion_window_ = kMinimumCongestionWindow;
+void TcpCubicSender::OnRetransmissionTimeout(bool packets_retransmitted) {
+  bytes_in_flight_ = 0;
+  if (packets_retransmitted) {
+    cubic_.Reset();
+    congestion_window_ = kMinimumCongestionWindow;
+  }
 }
 
 void TcpCubicSender::AckAccounting(QuicTime::Delta rtt) {
   if (rtt.IsInfinite() || rtt.IsZero()) {
     DVLOG(1) << "Ignoring rtt, because it's "
                << (rtt.IsZero() ? "Zero" : "Infinite");
     return;
   }
   // RTT can't be negative.
   DCHECK_LT(0, rtt.ToMicroseconds());
@@ skipping 29 matching lines @@
       hybrid_slow_start_.Reset(end_sequence_number_);
     }
     hybrid_slow_start_.Update(rtt, delay_min_);
     if (hybrid_slow_start_.Exit()) {
       slowstart_threshold_ = congestion_window_;
     }
   }
 }
 
 }  // namespace net