Deprecate FLAGS_quic_track_single_retransmission.

net/quic/quic_protocol.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.
 
 #ifndef NET_QUIC_QUIC_PROTOCOL_H_
 #define NET_QUIC_QUIC_PROTOCOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1349 matching lines @@
   // In flight packets have not been abandoned or lost.
   bool in_flight;
   // True if the packet can never be acked, so it can be removed.
   bool is_unackable;
   // True if the packet is an FEC packet.
   bool is_fec_packet;
   // True if the packet contains stream data from the crypto stream.
   bool has_crypto_handshake;
   // True if the packet needs padding if it's retransmitted.
   bool needs_padding;
-  // Stores the packet numbers of all transmissions of this packet.
-  // Must always be nullptr or have multiple elements.
-  // TODO(ianswett): Deprecate with quic_track_single_retransmission.
-  PacketNumberList* all_transmissions;
   // Stores the packet number of the next retransmission of this packet.
   // Zero if the packet has not been retransmitted.
   QuicPacketNumber retransmission;
   // Non-empty if there is a listener for this packet.
   std::list<AckListenerWrapper> ack_listeners;
 };
 static_assert(sizeof(QuicFrame) <= 64,
               "Keep the TransmissionInfo size to a cacheline.");
 
 // Struct to store the pending retransmission information.
@@ skipping 32 matching lines @@
       : iov(iov), iov_count(iov_count), total_length(total_length) {}
 
   const struct iovec* iov;
   const int iov_count;
   const size_t total_length;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PROTOCOL_H_