Repair the CWND reduction caused by spurious RTO's in QUIC's congestion

net/quic/congestion_control/send_algorithm_interface.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.
 //
 // The pure virtual class for send side congestion control algorithm.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_
 #define NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_
 
 #include <algorithm>
@@ skipping 49 matching lines @@
   virtual bool OnPacketSent(QuicTime sent_time,
                             QuicByteCount bytes_in_flight,
                             QuicPacketSequenceNumber sequence_number,
                             QuicByteCount bytes,
                             HasRetransmittableData is_retransmittable) = 0;
 
   // Called when the retransmission timeout fires.  Neither OnPacketAbandoned
   // nor OnPacketLost will be called for these packets.
   virtual void OnRetransmissionTimeout(bool packets_retransmitted) = 0;
 
+  // Called when the last retransmission timeout was spurious.
+  virtual void RevertRetransmissionTimeout() = 0;
+
   // Calculate the time until we can send the next packet.
   virtual QuicTime::Delta TimeUntilSend(
       QuicTime now,
       QuicByteCount bytes_in_flight,
       HasRetransmittableData has_retransmittable_data) const = 0;
 
   // What's the current estimated bandwidth in bytes per second.
   // Returns 0 when it does not have an estimate.
   virtual QuicBandwidth BandwidthEstimate() const = 0;
 
   // Get the send algorithm specific retransmission delay, called RTO in TCP,
   // Note 1: the caller is responsible for sanity checking this value.
   // Note 2: this will return zero if we don't have enough data for an estimate.
   virtual QuicTime::Delta RetransmissionDelay() const = 0;
 
   // Returns the size of the current congestion window in bytes.  Note, this is
   // not the *available* window.  Some send algorithms may not use a congestion
   // window and will return 0.
   virtual QuicByteCount GetCongestionWindow() const = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_