Deprecate quic_simple_packet_number_length_2.

net/quic/core/quic_flags_list.h

 // 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.
 
 // This file intentionally does not have header guards, it's included
 // inside a macro to generate values.
 
 // This file contains the list of QUIC protocol flags.
 
 // If true, QUIC BBR congestion control may be enabled via Finch and/or via QUIC
@@ skipping 65 matching lines @@
 // too large.
 QUIC_FLAG(bool, FLAGS_quic_close_connection_on_packet_too_large, true)
 
 // If true, use the CHLO packet size, not message size when determining how
 // large a REJ can be.
 QUIC_FLAG(bool, FLAGS_quic_use_chlo_packet_size, true)
 
 // If true, defer creation of new connection till its CHLO arrives.
 QUIC_FLAG(bool, FLAGS_quic_buffer_packet_till_chlo, true)
 
-// Deprecate QuicPacketCreator::next_packet_number_length_ because it's no
-// longer necessary.
-QUIC_FLAG(bool, FLAGS_quic_simple_packet_number_length_2, true)
-
 // If true, disables QUIC version less than 32.
 QUIC_FLAG(bool, FLAGS_quic_disable_pre_32, true)
 
 // If true, QUIC will enforce the MTU limit for connections that may require a
 // small MTU.
 QUIC_FLAG(bool, FLAGS_quic_enforce_mtu_limit, false)
 
 // Disable MTU probing if MTU probe causes ERR_MSG_TOO_BIG instead of aborting
 // the connection.
 QUIC_FLAG(bool, FLAGS_graceful_emsgsize_on_mtu_probe, true)
@@ skipping 18 matching lines @@
 
 // If true, allow server address change if it is because of mapped ipv4 address.
 QUIC_FLAG(bool, FLAGS_quic_allow_server_address_change_for_mapped_ipv4, true)
 
 // If true, disables QUIC version less than 34.
 QUIC_FLAG(bool, FLAGS_quic_disable_pre_34, false)
 
 // When true, decode the packet number from the largest received packet, rather
 // than the most recent.
 QUIC_FLAG(bool, FLAGS_quic_packet_numbers_largest_received, true)