Update from https://crrev.com/316786

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;
-
-// If true, the silent close option will be honored.
-bool FLAGS_quic_allow_silent_close = true;
-
-// If true, use std::cbrt instead of custom cube root.
-bool FLAGS_quic_use_std_cbrt = true;
+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, if min RTT and/or SRTT have not yet been set then initial RTT is
-// used to initialize them in a call to QuicConnection::GetStats.
-bool FLAGS_quic_use_initial_rtt_for_stats = true;
-
 // 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.
 bool FLAGS_quic_attach_ack_notifiers_to_packets = true;
 
-// If true, the AckNotifierManager is informed about new packets as soon as they
-// are serialized.
-bool FLAGS_quic_ack_notifier_informed_on_serialized = true;
-
 // If true, QUIC will use the new RTO that waits until an ack arrives to adjust
 // the congestion window.
 bool FLAGS_quic_use_new_rto = true;
 
 // Time period for which a given connection_id should live in the time-wait
 // state.
 int64 FLAGS_quic_time_wait_list_seconds = 5;
 
 // Currently, this number is quite conservative.  The max QPS limit for an
 // individual server silo is currently set to 1000 qps, though the actual max
 // that we see in the wild is closer to 450 qps. Regardless, this means that the
 // 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;
+
+// Use small QUIC packet sizes by default.
+bool FLAGS_quic_small_default_packet_size = true;