HTTP2 draft 13: support unknown frame types and settings types as extensions.

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
 
@@ skipping 267 matching lines @@
   DATA,
   SYN_STREAM,
   SYN_REPLY,
   RST_STREAM,
   SETTINGS,
   PING,
   GOAWAY,
   HEADERS,
   WINDOW_UPDATE,
   CREDENTIAL = 10,  // No longer valid.  Kept for identifiability.
-  BLOCKED,
   PUSH_PROMISE,
   CONTINUATION,
+  PRIORITY,
+  // BLOCKED and ALTSVC are recognized extensions.
+  BLOCKED,
   ALTSVC,
-  PRIORITY
 };
 
 // Flags on data packets.
 enum SpdyDataFlags {
   DATA_FLAG_NONE = 0x00,
   DATA_FLAG_FIN = 0x01,
   DATA_FLAG_END_SEGMENT = 0x02,
   DATA_FLAG_PADDED = 0x08,
   DATA_FLAG_COMPRESSED = 0x20,
 };
@@ skipping 741 matching lines @@
   SpdyFrameVisitor() {}
   virtual ~SpdyFrameVisitor() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SpdyFrameVisitor);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_PROTOCOL_H_