Fix to make sure QuicStreamSequencerBuffer release memory in time.

net/quic/core/quic_flags.cc

 // 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.
 
 #include "net/quic/core/quic_flags.h"
 
 // If true, it will return as soon as an error is detected while validating
 // CHLO.
 bool FLAGS_use_early_return_when_verifying_chlo = true;
 
@@ skipping 128 matching lines @@
 // instead of canceling and reregistering the alarm.
 bool FLAGS_quic_change_alarms_efficiently = false;
 
 // If true, requires handshake confirmations for all QUIC handshakes with
 // versions less than 33.
 bool FLAGS_quic_require_handshake_confirmation_pre33 = false;
 
 // If true, use the interval form of iteration over a PacketNumberQueue instead
 // of iterating over the individual numbers.
 bool FLAGS_quic_use_packet_number_queue_intervals = false;
+
+bool FLAGS_quic_sequencer_buffer_retire_block_in_time = true;