Add a new flag to require QUIC handshake confirmation, but only for versions before 33 FLAGS_quic_r…

net/quic/crypto/quic_crypto_server_config.cc

 // Copyright 2013 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/crypto/quic_crypto_server_config.h"
 
 #include <stdlib.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 1201 matching lines @@
     if (!is_unique) {
       info->reject_reasons.push_back(server_nonce_error);
     }
     DVLOG(1) << "Using server nonce, unique: " << is_unique;
     helper.ValidationComplete(QUIC_NO_ERROR, "");
     return;
   }
   // If we hit this block, the server nonce was empty.  If we're requiring
   // handshake confirmation for DoS reasons and there's no server nonce present,
   // reject the CHLO.
-  if (FLAGS_quic_require_handshake_confirmation) {
+  if (FLAGS_quic_require_handshake_confirmation ||
+      FLAGS_quic_require_handshake_confirmation_pre33) {
     info->reject_reasons.push_back(SERVER_NONCE_REQUIRED_FAILURE);
     helper.ValidationComplete(QUIC_NO_ERROR, "");
     return;
   }
 
   // We want to contact strike register only if there are no errors because it
   // is a RPC call and is expensive.
   if (found_error) {
     helper.ValidationComplete(QUIC_NO_ERROR, "");
     return;
@@ skipping 800 matching lines @@
       priority(0),
       source_address_token_boxer(nullptr) {}
 
 QuicCryptoServerConfig::Config::~Config() {
   STLDeleteElements(&key_exchanges);
 }
 
 QuicCryptoProof::QuicCryptoProof() {}
 QuicCryptoProof::~QuicCryptoProof() {}
 }  // namespace net