Deprecate FLAGS_quic_simplify_loss_detection.

net/quic/quic_sent_packet_manager.cc

 // Copyright 2013 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/quic_sent_packet_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 302 matching lines @@
   QuicPacketNumber packet_number = unacked_packets_.GetLeastUnacked();
   for (QuicUnackedPacketMap::iterator it = unacked_packets_.begin();
        it != unacked_packets_.end(); ++it, ++packet_number) {
     if (packet_number > ack_frame.largest_observed) {
       // These packets are still in flight.
       break;
     }
 
     if ((ack_frame.missing && ack_frame.packets.Contains(packet_number)) ||
         (!ack_frame.missing && !ack_frame.packets.Contains(packet_number))) {
-      // Don't continue to increase the nack count for packets not in flight.
-      if (FLAGS_quic_simplify_loss_detection || !it->in_flight) {
-        continue;
-      }
-      // Consider it multiple nacks when there is a gap between the missing
-      // packet and the largest observed, since the purpose of a nack
-      // threshold is to tolerate re-ordering.  This handles both StretchAcks
-      // and Forward Acks.
-      // The nack count only increases when the largest observed increases.
-      QuicPacketCount min_nacks = ack_frame.largest_observed - packet_number;
-      // Truncated acks can nack the largest observed, so use a min of 1.
-      if (min_nacks == 0) {
-        min_nacks = 1;
-      }
-      unacked_packets_.NackPacket(packet_number, min_nacks);
+      // Packet is still missing.
       continue;
     }
     // Packet was acked, so remove it from our unacked packet list.
     DVLOG(1) << ENDPOINT << "Got an ack for packet " << packet_number;
     // If data is associated with the most recent transmission of this
     // packet, then inform the caller.
     if (it->in_flight) {
       packets_acked_.push_back(std::make_pair(packet_number, it->bytes_sent));
     } else if (FLAGS_quic_loss_recovery_use_largest_acked &&
                !it->is_unackable) {
@@ skipping 675 matching lines @@
 TransmissionInfo* QuicSentPacketManager::GetMutableTransmissionInfo(
     QuicPacketNumber packet_number) {
   return unacked_packets_.GetMutableTransmissionInfo(packet_number);
 }
 
 void QuicSentPacketManager::RemoveObsoletePackets() {
   unacked_packets_.RemoveObsoletePackets();
 }
 
 }  // namespace net