Killing off QUICv12, including cleaning out all of the code for handling

net/quic/crypto/crypto_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_CRYPTO_CRYPTO_PROTOCOL_H_
 #define NET_QUIC_CRYPTO_CRYPTO_PROTOCOL_H_
 
 #include <string>
 
 #include "net/base/net_export.h"
@@ skipping 38 matching lines @@
 // Proof types (i.e. certificate types)
 // NOTE: although it would be silly to do so, specifying both kX509 and kX59R
 // is allowed and is equivalent to specifying only kX509.
 const QuicTag kX509 = TAG('X', '5', '0', '9');  // X.509 certificate, all key
                                                 // types
 const QuicTag kX59R = TAG('X', '5', '9', 'R');  // X.509 certificate, RSA keys
                                                 // only
 const QuicTag kCHID = TAG('C', 'H', 'I', 'D');  // Channel ID.
 
 // Client hello tags
-// TODO(rch): Remove once we remove QUIC_VERSION_12.
-const QuicTag kVERS = TAG('V', 'E', 'R', 'S');  // Version (obsolete)
 const QuicTag kVER  = TAG('V', 'E', 'R', '\0'); // Version (new)
 const QuicTag kNONC = TAG('N', 'O', 'N', 'C');  // The client's nonce
 const QuicTag kKEXS = TAG('K', 'E', 'X', 'S');  // Key exchange methods
 const QuicTag kAEAD = TAG('A', 'E', 'A', 'D');  // Authenticated
                                                 // encryption algorithms
 const QuicTag kCGST = TAG('C', 'G', 'S', 'T');  // Congestion control
                                                 // feedback types
 const QuicTag kICSL = TAG('I', 'C', 'S', 'L');  // Idle connection state
                                                 // lifetime
 const QuicTag kKATO = TAG('K', 'A', 'T', 'O');  // Keepalive timeout
@@ skipping 62 matching lines @@
 // kClientHelloMinimumSize is the minimum size of a client hello. Client hellos
 // will have PAD tags added in order to ensure this minimum is met and client
 // hellos smaller than this will be an error. This minimum size reduces the
 // amplification factor of any mirror DoS attack.
 //
 // A client may pad an inchoate client hello to a size larger than
 // kClientHelloMinimumSize to make it more likely to receive a complete
 // rejection message.
 const size_t kClientHelloMinimumSize = 1024;
 
-// kClientHelloMinimumSizeOld is the previous value of kClientHelloMinimumSize.
-// To support old clients, the server only enforces this size.
-// TODO(wtc): Replace it with kClientHelloMinimumSize when we drop support for
-// QUIC_VERSION_12 clients.
-const size_t kClientHelloMinimumSizeOld = 512;
-
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_CRYPTO_PROTOCOL_H_