Disable QUIC versions 33 and earlier, protected by FLAGS_quic_disable_pre_34.

net/quic/core/quic_protocol.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_QUIC_QUIC_PROTOCOL_H_
 #define NET_QUIC_QUIC_PROTOCOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 357 matching lines @@
   QUIC_VERSION_UNSUPPORTED = 0,
 
   QUIC_VERSION_30 = 30,  // Add server side support of cert transparency.
   QUIC_VERSION_31 = 31,  // Adds a hash of the client hello to crypto proof.
   QUIC_VERSION_32 = 32,  // FEC related fields are removed from wire format.
   QUIC_VERSION_33 = 33,  // Adds diversification nonces.
   QUIC_VERSION_34 = 34,  // Deprecates entropy, removes private flag from packet
                          // header, uses new ack and stop waiting wire format.
   QUIC_VERSION_35 = 35,  // Allows endpoints to independently set stream limit.
   QUIC_VERSION_36 = 36,  // Add support to force HOL blocking.
+
+  // IMPORTANT: if you are adding to this std::list, follow the instructions at
+  // http://sites/quic/adding-and-removing-versions
 };
 
 // This vector contains QUIC versions which we currently support.
 // This should be ordered such that the highest supported version is the first
 // element, with subsequent elements in descending order (versions can be
 // skipped as necessary).
 //
 // IMPORTANT: if you are adding to this list, follow the instructions at
 // http://sites/quic/adding-and-removing-versions
 static const QuicVersion kSupportedQuicVersions[] = {
@@ skipping 1000 matching lines @@
  public:
   explicit QuicVersionManager(QuicVersionVector supported_versions);
   ~QuicVersionManager();
 
   // Returns supported versions based on flags.
   const QuicVersionVector& GetSupportedVersions();
 
  private:
   // FLAGS_quic_disable_pre_32
   bool disable_pre_32_;
+  // FLAGS_quic_disable_pre_34
+  bool disable_pre_34_;
   // FLAGS_quic_enable_version_35
   bool enable_version_35_;
   // FLAGS_quic_enable_version_36_v2
   bool enable_version_36_;
   // The list of versions that may be supported.
   QuicVersionVector allowed_supported_versions_;
   // This vector contains QUIC versions which are currently supported based
   // on flags.
   QuicVersionVector filtered_supported_versions_;
 };
@@ skipping 122 matching lines @@
       : iov(iov), iov_count(iov_count), total_length(total_length) {}
 
   const struct iovec* iov;
   const int iov_count;
   const size_t total_length;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PROTOCOL_H_