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

net/http2/hpack/decoder/hpack_string_decoder.cc

-// 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.
-
-#include "net/http2/hpack/decoder/hpack_string_decoder.h"
-
-#include <sstream>
-
-namespace net {
-
-std::string HpackStringDecoder::DebugString() const {
-  std::stringstream ss;
-  ss << "HpackStringDecoder(state=" << StateToString(state_)
-     << ", length=" << length_decoder_.DebugString()
-     << ", remaining=" << remaining_
-     << ", huffman=" << (huffman_encoded_ ? "true)" : "false)");
-  return ss.str();
-}
-
-// static
-std::string HpackStringDecoder::StateToString(StringDecoderState v) {
-  switch (v) {
-    case kStartDecodingLength:
-      return "kStartDecodingLength";
-    case kDecodingString:
-      return "kDecodingString";
-    case kResumeDecodingLength:
-      return "kResumeDecodingLength";
-  }
-  std::stringstream ss;
-  ss << "UNKNOWN_STATE(" << static_cast<uint32_t>(v) << ")";
-  return ss.str();
-}
-
-std::ostream& operator<<(std::ostream& out, const HpackStringDecoder& v) {
-  return out << v.DebugString();
-}
-
-}  // namespace net