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

net/http2/decoder/payload_decoders/ping_payload_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/decoder/payload_decoders/ping_payload_decoder.h"
-
-#include "base/logging.h"
-#include "net/http2/decoder/http2_frame_decoder_listener.h"
-#include "net/http2/http2_constants.h"
-
-namespace net {
-namespace {
-constexpr auto kOpaqueSize = Http2PingFields::EncodedSize();
-}
-
-DecodeStatus PingPayloadDecoder::StartDecodingPayload(FrameDecoderState* state,
-                                                      DecodeBuffer* db) {
-  const Http2FrameHeader& frame_header = state->frame_header();
-  const uint32_t total_length = frame_header.payload_length;
-
-  DVLOG(2) << "PingPayloadDecoder::StartDecodingPayload: " << frame_header;
-  DCHECK_EQ(Http2FrameType::PING, frame_header.type);
-  DCHECK_LE(db->Remaining(), total_length);
-  DCHECK_EQ(0, frame_header.flags & ~(Http2FrameFlag::FLAG_ACK));
-
-  // Is the payload entirely in the decode buffer and is it the correct size?
-  // Given the size of the header and payload (17 bytes total), this is most
-  // likely the case the vast majority of the time.
-  if (db->Remaining() == kOpaqueSize && total_length == kOpaqueSize) {
-    // Special case this situation as it allows us to avoid any copying;
-    // the other path makes two copies, first into the buffer in
-    // Http2StructureDecoder as it accumulates the 8 bytes of opaque data,
-    // and a second copy into the Http2PingFields member of in this class.
-    // This supports the claim that this decoder is (mostly) non-buffering.
-    static_assert(sizeof(Http2PingFields) == kOpaqueSize,
-                  "If not, then can't enter this block!");
-    auto ping = reinterpret_cast<const Http2PingFields*>(db->cursor());
-    if (frame_header.IsAck()) {
-      state->listener()->OnPingAck(frame_header, *ping);
-    } else {
-      state->listener()->OnPing(frame_header, *ping);
-    }
-    db->AdvanceCursor(kOpaqueSize);
-    return DecodeStatus::kDecodeDone;
-  }
-  state->InitializeRemainders();
-  return HandleStatus(
-      state, state->StartDecodingStructureInPayload(&ping_fields_, db));
-}
-
-DecodeStatus PingPayloadDecoder::ResumeDecodingPayload(FrameDecoderState* state,
-                                                       DecodeBuffer* db) {
-  DVLOG(2) << "ResumeDecodingPayload: remaining_payload="
-           << state->remaining_payload();
-  DCHECK_EQ(Http2FrameType::PING, state->frame_header().type);
-  DCHECK_LE(db->Remaining(), state->frame_header().payload_length);
-  return HandleStatus(
-      state, state->ResumeDecodingStructureInPayload(&ping_fields_, db));
-}
-
-DecodeStatus PingPayloadDecoder::HandleStatus(FrameDecoderState* state,
-                                              DecodeStatus status) {
-  DVLOG(2) << "HandleStatus: status=" << status
-           << "; remaining_payload=" << state->remaining_payload();
-  if (status == DecodeStatus::kDecodeDone) {
-    if (state->remaining_payload() == 0) {
-      const Http2FrameHeader& frame_header = state->frame_header();
-      if (frame_header.IsAck()) {
-        state->listener()->OnPingAck(frame_header, ping_fields_);
-      } else {
-        state->listener()->OnPing(frame_header, ping_fields_);
-      }
-      return DecodeStatus::kDecodeDone;
-    }
-    // Payload is too long.
-    return state->ReportFrameSizeError();
-  }
-  // Not done decoding the structure. Either we've got more payload to decode,
-  // or we've run out because the payload is too short.
-  DCHECK(
-      (status == DecodeStatus::kDecodeInProgress &&
-       state->remaining_payload() > 0) ||
-      (status == DecodeStatus::kDecodeError && state->remaining_payload() == 0))
-      << "\n status=" << status
-      << "; remaining_payload=" << state->remaining_payload();
-  return status;
-}
-
-}  // namespace net