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

net/http2/hpack/decoder/hpack_decoder_string_buffer.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_DECODER_HPACK_DECODER_STRING_BUFFER_H_
-#define NET_HTTP2_HPACK_DECODER_HPACK_DECODER_STRING_BUFFER_H_
-
-// HpackDecoderStringBuffer helps an HPACK decoder to avoid copies of a string
-// literal (name or value) except when necessary (e.g. when split across two
-// or more HPACK block fragments).
-
-#include <stddef.h>
-
-#include <ostream>
-#include <string>
-
-#include "base/macros.h"
-#include "base/strings/string_piece.h"
-#include "net/base/net_export.h"
-#include "net/http2/hpack/huffman/http2_hpack_huffman_decoder.h"
-
-namespace net {
-
-class NET_EXPORT_PRIVATE HpackDecoderStringBuffer {
- public:
-  enum class State : uint8_t { RESET, COLLECTING, COMPLETE };
-  enum class Backing : uint8_t { RESET, UNBUFFERED, BUFFERED, STATIC };
-
-  HpackDecoderStringBuffer();
-  ~HpackDecoderStringBuffer();
-
-  void Reset();
-  void Set(base::StringPiece value, bool is_static);
-
-  // Note that for Huffman encoded strings the length of the string after
-  // decoding may be larger (expected), the same or even smaller; the latter
-  // are unlikely, but possible if the encoder makes odd choices.
-  void OnStart(bool huffman_encoded, size_t len);
-  bool OnData(const char* data, size_t len);
-  bool OnEnd();
-  void BufferStringIfUnbuffered();
-  size_t BufferedLength() const;
-
-  base::StringPiece str() const;
-
-  State state_for_testing() const { return state_; }
-  Backing backing_for_testing() const { return backing_; }
-  void OutputDebugStringTo(std::ostream& out) const;
-
- private:
-  // Storage for the string being buffered, if buffering is necessary
-  // (e.g. if Huffman encoded, buffer_ is storage for the decoded string).
-  std::string buffer_;
-
-  // The StringPiece to be returned by HpackDecoderStringBuffer::str(). If a
-  // string has been collected, but not buffered, value_ points to that string.
-  base::StringPiece value_;
-
-  // The decoder to use if the string is Huffman encoded.
-  HpackHuffmanDecoder decoder_;
-
-  // Count of bytes not yet passed to OnData.
-  size_t remaining_len_ = 0;
-
-  // Is the HPACK string Huffman encoded?
-  bool is_huffman_encoded_ = false;
-
-  // State of the string decoding process.
-  State state_;
-
-  // Where is the string stored?
-  Backing backing_;
-
-  DISALLOW_COPY_AND_ASSIGN(HpackDecoderStringBuffer);
-};
-
-NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
-                                            const HpackDecoderStringBuffer& v);
-
-}  // namespace net
-
-#endif  // NET_HTTP2_HPACK_DECODER_HPACK_DECODER_STRING_BUFFER_H_