diff --git a/spdy/core/hpack/hpack_constants.h b/spdy/core/hpack/hpack_constants.h
new file mode 100644
index 0000000..3f4026b
--- /dev/null
+++ b/spdy/core/hpack/hpack_constants.h
@@ -0,0 +1,95 @@
+// 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 QUICHE_SPDY_CORE_HPACK_HPACK_CONSTANTS_H_
+#define QUICHE_SPDY_CORE_HPACK_HPACK_CONSTANTS_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+#include "net/third_party/quiche/src/spdy/platform/api/spdy_export.h"
+
+// All section references below are to
+// http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-08
+
+namespace spdy {
+
+// An HpackPrefix signifies |bits| stored in the top |bit_size| bits
+// of an octet.
+struct HpackPrefix {
+  uint8_t bits;
+  size_t bit_size;
+};
+
+// Represents a symbol and its Huffman code (stored in most-significant bits).
+struct HpackHuffmanSymbol {
+  uint32_t code;
+  uint8_t length;
+  uint16_t id;
+};
+
+// An entry in the static table. Must be a POD in order to avoid static
+// initializers, i.e. no user-defined constructors or destructors.
+struct HpackStaticEntry {
+  const char* const name;
+  const size_t name_len;
+  const char* const value;
+  const size_t value_len;
+};
+
+class HpackHuffmanTable;
+class HpackStaticTable;
+
+// Defined in RFC 7540, 6.5.2.
+const uint32_t kDefaultHeaderTableSizeSetting = 4096;
+
+// RFC 7541, 5.2: Flag for a string literal that is stored unmodified (i.e.,
+// without Huffman encoding).
+const HpackPrefix kStringLiteralIdentityEncoded = {0x0, 1};
+
+// RFC 7541, 5.2: Flag for a Huffman-coded string literal.
+const HpackPrefix kStringLiteralHuffmanEncoded = {0x1, 1};
+
+// RFC 7541, 6.1: Opcode for an indexed header field.
+const HpackPrefix kIndexedOpcode = {0b1, 1};
+
+// RFC 7541, 6.2.1: Opcode for a literal header field with incremental indexing.
+const HpackPrefix kLiteralIncrementalIndexOpcode = {0b01, 2};
+
+// RFC 7541, 6.2.2: Opcode for a literal header field without indexing.
+const HpackPrefix kLiteralNoIndexOpcode = {0b0000, 4};
+
+// RFC 7541, 6.2.3: Opcode for a literal header field which is never indexed.
+// Currently unused.
+// const HpackPrefix kLiteralNeverIndexOpcode = {0b0001, 4};
+
+// RFC 7541, 6.3: Opcode for maximum header table size update. Begins a
+// varint-encoded table size with a 5-bit prefix.
+const HpackPrefix kHeaderTableSizeUpdateOpcode = {0b001, 3};
+
+// Symbol code table from RFC 7541, "Appendix C. Huffman Code".
+SPDY_EXPORT_PRIVATE const std::vector<HpackHuffmanSymbol>&
+HpackHuffmanCodeVector();
+
+// Static table from RFC 7541, "Appendix B. Static Table Definition".
+SPDY_EXPORT_PRIVATE const std::vector<HpackStaticEntry>&
+HpackStaticTableVector();
+
+// 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.
+SPDY_EXPORT_PRIVATE const HpackHuffmanTable& ObtainHpackHuffmanTable();
+
+// Returns a HpackStaticTable instance initialized with |kHpackStaticTable|.
+// The instance is read-only, has static lifetime, and is safe to share amoung
+// threads. This function is thread-safe.
+SPDY_EXPORT_PRIVATE const HpackStaticTable& ObtainHpackStaticTable();
+
+// Pseudo-headers start with a colon.  (HTTP2 8.1.2.1., HPACK 3.1.)
+const char kPseudoHeaderPrefix = ':';
+
+}  // namespace spdy
+
+#endif  // QUICHE_SPDY_CORE_HPACK_HPACK_CONSTANTS_H_