relnote: Deprecate FLAGS_quic_dont_ack_acks.

net/quic/quic_connection.cc

 // 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.
 
 #include "net/quic/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
@@ skipping 999 matching lines @@
       return;
     }
   }
   if (!last_close_frames_.empty()) {
     CloseConnection(last_close_frames_[0].error_code, true);
     DCHECK(!connected_);
     return;
   }
 
   // If there are new missing packets to report, send an ack immediately.
-  if ((!FLAGS_quic_dont_ack_acks || ShouldLastPacketInstigateAck()) &&
+  if (ShouldLastPacketInstigateAck() &&
       received_packet_manager_.HasNewMissingPackets()) {
     ack_queued_ = true;
     ack_alarm_->Cancel();
   }
 
   UpdateStopWaitingCount();
   ClearLastFrames();
   MaybeCloseIfTooManyOutstandingPackets();
 }
 
@@ skipping 1289 matching lines @@
       sequence_number_of_last_sent_packet_ + packets_between_mtu_probes_ + 1;
   ++mtu_probe_count_;
 
   DVLOG(2) << "Sending a path MTU discovery packet #" << mtu_probe_count_;
   SendMtuDiscoveryPacket(mtu_discovery_target_);
 
   DCHECK(!mtu_discovery_alarm_->IsSet());
 }
 
 }  // namespace net