[SPDY] Incorporate latest framing changes from HTTP2 into SPDY 4 as SPDY 4a2.

net/socket/next_proto.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_SOCKET_NEXT_PROTO_H_
 #define NET_SOCKET_NEXT_PROTO_H_
 
 namespace net {
 
 // Next Protocol Negotiation (NPN), if successful, results in agreement on an
 // application-level string that specifies the application level protocol to
 // use over the TLS connection. NextProto enumerates the application level
 // protocols that we recognise.
 enum NextProto {
   kProtoUnknown = 0,
   kProtoHTTP11 = 1,
 
   kProtoSPDY1 = 2,
   kProtoSPDYMinimumVersion = kProtoSPDY1,
   kProtoSPDY2 = 3,
   kProtoSPDY21 = 4,
   kProtoSPDY3 = 5,
   kProtoSPDY31 = 6,
-  kProtoSPDY4a1 = 7,
-  kProtoSPDYMaximumVersion = kProtoSPDY4a1,
+  kProtoSPDY4a2 = 7,
+  kProtoSPDYMaximumVersion = kProtoSPDY4a2,
 
   kProtoMaximumVersion = 7,
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_NEXT_PROTO_H_