HPACK: encode :pseudo and indexed headers first.

net/spdy/hpack_constants.h

 // Copyright 2014 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_SPDY_HPACK_CONSTANTS_H_
 #define NET_SPDY_HPACK_CONSTANTS_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 55 matching lines @@
 const HpackPrefix kHeaderTableSizeUpdateOpcode = { 0x1, 3 };
 
 // Returns symbol code table from "Appendix C. Huffman Codes".
 NET_EXPORT_PRIVATE std::vector<HpackHuffmanSymbol> HpackHuffmanCode();
 
 // Returns a HpackHuffmanTable instance initialized with |kHpackHuffmanCode|.
 // The instance is read-only, has static lifetime, and is safe to share amoung
 // threads. This function is thread-safe.
 NET_EXPORT_PRIVATE const HpackHuffmanTable& ObtainHpackHuffmanTable();
 
+// Pseudo-headers start with a colon.  (HTTP2 8.1.2.1., HPACK 3.1.)
+const char kPseudoHeaderPrefix = ':';
+
 }  // namespace net
 
 #endif  // NET_SPDY_HPACK_CONSTANTS_H_