relnote: Add a new LazyFack loss detection to QUIC triggered by the LFAK connection option.

net/quic/core/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/core/quic_sent_packet_manager.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 134 matching lines @@
     use_new_rto_ = true;
   }
   if (config.HasReceivedConnectionOptions() &&
       ContainsQuicTag(config.ReceivedConnectionOptions(), kTIME)) {
     general_loss_algorithm_.SetLossDetectionType(kTime);
   }
   if (config.HasReceivedConnectionOptions() &&
       ContainsQuicTag(config.ReceivedConnectionOptions(), kATIM)) {
     general_loss_algorithm_.SetLossDetectionType(kAdaptiveTime);
   }
+  if (FLAGS_quic_enable_lazy_fack &&
+      config.HasReceivedConnectionOptions() &&
+      ContainsQuicTag(config.ReceivedConnectionOptions(), kLFAK)) {
+    general_loss_algorithm_.SetLossDetectionType(kLazyFack);
+  }
   if (config.HasClientSentConnectionOption(kUNDO, perspective_)) {
     undo_pending_retransmits_ = true;
   }
   if (FLAGS_quic_conservative_handshake_retransmits &&
       config.HasClientSentConnectionOption(kCONH, perspective_)) {
     conservative_handshake_retransmits_ = true;
   }
   send_algorithm_->SetFromConfig(config, perspective_);
 
   if (network_change_visitor_ != nullptr) {
@@ skipping 841 matching lines @@
 
 void QuicSentPacketManager::RemoveObsoletePackets() {
   unacked_packets_.RemoveObsoletePackets();
 }
 
 void QuicSentPacketManager::OnApplicationLimited() {
   send_algorithm_->OnApplicationLimited(unacked_packets_.bytes_in_flight());
 }
 
 }  // namespace net