deprecate -FLAGS_quic_reloadable_flag_quic_disable_version_34 and remove support for QUIC v34.

net/quic/core/quic_version_manager.cc

 // Copyright (c) 2016 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_version_manager.h"
 
 #include "net/quic/core/quic_flags.h"
 #include "net/quic/core/quic_versions.h"
 
 namespace net {
 
 QuicVersionManager::QuicVersionManager(QuicVersionVector supported_versions)
     : enable_version_39_(base::GetFlag(FLAGS_quic_enable_version_39)),
       enable_version_38_(FLAGS_quic_reloadable_flag_quic_enable_version_38),
       enable_version_37_(FLAGS_quic_reloadable_flag_quic_enable_version_37),
       enable_version_36_(FLAGS_quic_reloadable_flag_quic_enable_version_36_v3),
-      disable_version_34_(FLAGS_quic_reloadable_flag_quic_disable_version_34),
       allowed_supported_versions_(supported_versions),
       filtered_supported_versions_(
           FilterSupportedVersions(supported_versions)) {}
 
 QuicVersionManager::~QuicVersionManager() {}
 
 const QuicVersionVector& QuicVersionManager::GetSupportedVersions() {
   MaybeRefilterSupportedVersions();
   return filtered_supported_versions_;
 }
 
 void QuicVersionManager::MaybeRefilterSupportedVersions() {
   if (enable_version_39_ != base::GetFlag(FLAGS_quic_enable_version_39) ||
       enable_version_38_ != FLAGS_quic_reloadable_flag_quic_enable_version_38 ||
       enable_version_37_ != FLAGS_quic_reloadable_flag_quic_enable_version_37 ||
       enable_version_36_ !=
-          FLAGS_quic_reloadable_flag_quic_enable_version_36_v3 ||
-      disable_version_34_ !=
-          FLAGS_quic_reloadable_flag_quic_disable_version_34) {
+          FLAGS_quic_reloadable_flag_quic_enable_version_36_v3) {
     enable_version_39_ = base::GetFlag(FLAGS_quic_enable_version_39);
     enable_version_38_ = FLAGS_quic_reloadable_flag_quic_enable_version_38;
     enable_version_37_ = FLAGS_quic_reloadable_flag_quic_enable_version_37;
     enable_version_36_ = FLAGS_quic_reloadable_flag_quic_enable_version_36_v3;
-    disable_version_34_ = FLAGS_quic_reloadable_flag_quic_disable_version_34;
     RefilterSupportedVersions();
   }
 }
 
 void QuicVersionManager::RefilterSupportedVersions() {
   filtered_supported_versions_ =
       FilterSupportedVersions(allowed_supported_versions_);
 }
 
 }  // namespace net