Deprecate FLAGS_quic_track_single_retransmission.

net/quic/quic_unacked_packet_map.h

 // Copyright 2014 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.
 
 #ifndef NET_QUIC_QUIC_UNACKED_PACKET_MAP_H_
 #define NET_QUIC_QUIC_UNACKED_PACKET_MAP_H_
 
 #include <stddef.h>
 
 #include <deque>
@@ skipping 67 matching lines @@
   // Returns true if there are any unacked packets which have retransmittable
   // frames.
   bool HasUnackedRetransmittableFrames() const;
 
   // Returns the largest packet number that has been sent.
   QuicPacketNumber largest_sent_packet() const { return largest_sent_packet_; }
 
   // Returns the largest packet number that has been acked.
   QuicPacketNumber largest_observed() const { return largest_observed_; }
 
-  bool track_single_retransmission() const {
-    return track_single_retransmission_;
-  }
-
   // Returns the sum of bytes from all packets in flight.
   QuicByteCount bytes_in_flight() const { return bytes_in_flight_; }
 
   // Returns the smallest packet number of a serialized packet which has not
   // been acked by the peer.  If there are no unacked packets, returns 0.
   QuicPacketNumber GetLeastUnacked() const;
 
   typedef std::deque<TransmissionInfo> UnackedPacketMap;
 
   typedef UnackedPacketMap::const_iterator const_iterator;
@@ skipping 87 matching lines @@
   // be removed from the map and the new entry's retransmittable frames will be
   // set to nullptr.
   UnackedPacketMap unacked_packets_;
   // The packet at the 0th index of unacked_packets_.
   QuicPacketNumber least_unacked_;
 
   QuicByteCount bytes_in_flight_;
   // Number of retransmittable crypto handshake packets.
   size_t pending_crypto_packet_count_;
 
-  // Latched copy of gfe2_reloadable_flag_quic_track_single_retransmission.
-  const bool track_single_retransmission_;
-
   DISALLOW_COPY_AND_ASSIGN(QuicUnackedPacketMap);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_UNACKED_PACKET_MAP_H_