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

net/http2/decoder/payload_decoders/headers_payload_decoder.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_DECODER_PAYLOAD_DECODERS_HEADERS_PAYLOAD_DECODER_H_
-#define NET_HTTP2_DECODER_PAYLOAD_DECODERS_HEADERS_PAYLOAD_DECODER_H_
-
-// Decodes the payload of a HEADERS frame.
-
-#include "net/base/net_export.h"
-#include "net/http2/decoder/decode_buffer.h"
-#include "net/http2/decoder/decode_status.h"
-#include "net/http2/decoder/frame_decoder_state.h"
-#include "net/http2/http2_structures.h"
-
-namespace net {
-namespace test {
-class HeadersPayloadDecoderPeer;
-}  // namespace test
-
-class NET_EXPORT_PRIVATE HeadersPayloadDecoder {
- public:
-  // States during decoding of a HEADERS frame, unless the fast path kicks
-  // in, in which case the state machine will be bypassed.
-  enum class PayloadState {
-    // The PADDED flag is set, and we now need to read the Pad Length field
-    // (the first byte of the payload, after the common frame header).
-    kReadPadLength,
-
-    // The PRIORITY flag is set, and we now need to read the fixed size priority
-    // fields (E, Stream Dependency, Weight) into priority_fields_.  Calls on
-    // OnHeadersPriority if completely decodes those fields.
-    kStartDecodingPriorityFields,
-
-    // The decoder passes the non-padding portion of the remaining payload
-    // (i.e. the HPACK block fragment) to the listener's OnHpackFragment method.
-    kReadPayload,
-
-    // The decoder has finished with the HPACK block fragment, and is now
-    // ready to skip the trailing padding, if the frame has any.
-    kSkipPadding,
-
-    // The fixed size fields weren't all available when the decoder first tried
-    // to decode them (state kStartDecodingPriorityFields); this state resumes
-    // the decoding when ResumeDecodingPayload is called later.
-    kResumeDecodingPriorityFields,
-  };
-
-  // Starts the decoding of a HEADERS frame's payload, and completes it if
-  // the entire payload is in the provided decode buffer.
-  DecodeStatus StartDecodingPayload(FrameDecoderState* state, DecodeBuffer* db);
-
-  // Resumes decoding a HEADERS frame's payload that has been split across
-  // decode buffers.
-  DecodeStatus ResumeDecodingPayload(FrameDecoderState* state,
-                                     DecodeBuffer* db);
-
- private:
-  friend class test::HeadersPayloadDecoderPeer;
-
-  PayloadState payload_state_;
-  Http2PriorityFields priority_fields_;
-};
-
-}  // namespace net
-
-#endif  // NET_HTTP2_DECODER_PAYLOAD_DECODERS_HEADERS_PAYLOAD_DECODER_H_