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

net/http2/decoder/payload_decoders/data_payload_decoder.h

Index: net/http2/decoder/payload_decoders/data_payload_decoder.h
diff --git a/net/http2/decoder/payload_decoders/data_payload_decoder.h b/net/http2/decoder/payload_decoders/data_payload_decoder.h
new file mode 100644
index 0000000000000000000000000000000000000000..2fe09596a670baab9e0c48305e5f98eb7a0ee5da
--- /dev/null
+++ b/net/http2/decoder/payload_decoders/data_payload_decoder.h
@@ -0,0 +1,54 @@
+// 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_DATA_PAYLOAD_DECODER_H_
+#define NET_HTTP2_DECODER_PAYLOAD_DECODERS_DATA_PAYLOAD_DECODER_H_
+
+// Decodes the payload of a DATA 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"
+
+namespace net {
+namespace test {
+class DataPayloadDecoderPeer;
+}  // namespace test
+
+class NET_EXPORT_PRIVATE DataPayloadDecoder {
+ public:
+  // States during decoding of a DATA frame.
+  enum class PayloadState {
+    // The frame is padded and we need to read the PAD_LENGTH field (1 byte),
+    // and then call OnPadLength
+    kReadPadLength,
+
+    // Report the non-padding portion of the payload to the listener's
+    // OnDataPayload method.
+    kReadPayload,
+
+    // The decoder has finished with the non-padding portion of the payload,
+    // and is now ready to skip the trailing padding, if the frame has any.
+    kSkipPadding,
+  };
+
+  // Starts decoding a DATA 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 DATA frame's payload that has been split across
+  // decode buffers.
+  DecodeStatus ResumeDecodingPayload(FrameDecoderState* state,
+                                     DecodeBuffer* db);
+
+ private:
+  friend class test::DataPayloadDecoderPeer;
+
+  PayloadState payload_state_;
+};
+
+}  // namespace net
+
+#endif  // NET_HTTP2_DECODER_PAYLOAD_DECODERS_DATA_PAYLOAD_DECODER_H_