Revert of Add new HTTP/2 and HPACK decoder in net/http2/.

net/http2/hpack/tools/hpack_example.h

-// Copyright 2016 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_HTTP2_HPACK_TOOLS_HPACK_EXAMPLE_H_
-#define NET_HTTP2_HPACK_TOOLS_HPACK_EXAMPLE_H_
-
-// Parses HPACK examples in the format seen in the HPACK specification,
-// RFC 7541. For example:
-//
-//       10                                      | == Literal never indexed ==
-//       08                                      |   Literal name (len = 8)
-//       7061 7373 776f 7264                     | password
-//       06                                      |   Literal value (len = 6)
-//       7365 6372 6574                          | secret
-//                                               | -> password: secret
-//
-// (excluding the leading "//").
-
-#include <string>
-
-#include "base/strings/string_piece.h"
-
-namespace net {
-namespace test {
-
-std::string HpackExampleToStringOrDie(base::StringPiece example);
-
-}  // namespace test
-}  // namespace net
-
-#endif  // NET_HTTP2_HPACK_TOOLS_HPACK_EXAMPLE_H_