[SPDY] Add flag and about:flags entry for SPDY/4 alpha 1

net/spdy/spdy_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.
 
 // This file contains some protocol structures for use with SPDY 2 and 3
 // The SPDY 2 spec can be found at:
 // http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-draft2
 // The SPDY 3 spec can be found at:
 // http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-draft3
 
 #ifndef NET_SPDY_SPDY_PROTOCOL_H_
 #define NET_SPDY_SPDY_PROTOCOL_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string_piece.h"
 #include "base/sys_byteorder.h"
 #include "net/base/net_export.h"
 #include "net/spdy/spdy_bitmasks.h"
 
 namespace net {
 
+// TODO(akalin): Convert this to an enum.
 const int32 kSpdyVersion2 = 2;
 const int32 kSpdyVersion3 = 3;
+const int32 kSpdyVersion4 = 4;
 
 // A SPDY stream id is a 31 bit entity.
 typedef uint32 SpdyStreamId;
 
 // Specifies the stream ID used to denote the current session (for
 // flow control).
 const SpdyStreamId kSessionFlowControlStreamId = 0;
 
 // Initial window size for a Spdy stream.
 const int32 kSpdyStreamInitialWindowSize = 64 * 1024;  // 64 KBytes
@@ skipping 658 matching lines @@
 
  private:
   size_t size_;
   bool owns_buffer_;
   DISALLOW_COPY_AND_ASSIGN(SpdyFrame);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_PROTOCOL_H_