Enable QUIC's pacing by default on all QUIC connections by setting

net/quic/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/quic_flags.h"
 
 bool FLAGS_quic_allow_oversized_packets_for_test = false;
 
 // When true, the use time based loss detection instead of nack.
 bool FLAGS_quic_use_time_loss_detection = false;
@@ skipping 21 matching lines @@
 // WritePacket, rather than after in QUIC.
 bool FLAGS_quic_record_send_time_before_write = false;
 
 // If true, enables the QUIC bandwidth resumption experiment (triggered by
 // Chrome/Finch).
 bool FLAGS_quic_enable_bandwidth_resumption_experiment = true;
 
 // If true, QUIC congestion control will be paced.  If false, pacing may be
 // controlled by QUIC connection options in the config or by enabling BBR
 // congestion control.
-bool FLAGS_quic_enable_pacing = false;
+bool FLAGS_quic_enable_pacing = true;
 
 // If true, then the source address tokens generated for QUIC connects will
 // store multiple addresses.
 bool FLAGS_quic_use_multiple_address_in_source_tokens = false;
 
 // If true, uses the last sent packet for the RTO timer instead of the earliest.
 bool FLAGS_quic_rto_uses_last_sent = true;
 
 // If true, attach QuicAckNotifiers to packets rather than individual stream
 // frames.
@@ skipping 13 matching lines @@
 // longest time-wait list we should see is 5 seconds * 1000 qps = 5000.  If we
 // allow for an order of magnitude leeway, we have 50000.
 //
 // Maximum number of connections on the time-wait list. A negative value implies
 // no configured limit.
 int64 FLAGS_quic_time_wait_list_max_connections = 50000;
 
 // If true, limit the number of connections on the quic time-wait list using a
 // flag.
 bool FLAGS_quic_limit_time_wait_list_size = true;