Add Http2FrameDecoderAdapter.

net/spdy/http2_frame_decoder_adapter.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_SPDY_HTTP2_FRAME_DECODER_ADAPTER_H_
+#define NET_SPDY_HTTP2_FRAME_DECODER_ADAPTER_H_
+
+// Provides a SpdyFramerDecoderAdapter that uses Http2FrameDecoder for decoding
+// HTTP/2 frames. The adapter does not directly decode HPACK, but instead calls
+// SpdyFramer::GetHpackDecoderForAdapter() to get the decoder to be used.
+
+#include <memory>
+
+#include "net/spdy/spdy_framer.h"
+#include "net/spdy/spdy_framer_decoder_adapter.h"
+
+namespace net {
+
+std::unique_ptr<SpdyFramerDecoderAdapter> CreateHttp2FrameDecoderAdapter(
+    SpdyFramer* outer_framer);
+
+}  // namespace net
+
+#endif  // NET_SPDY_HTTP2_FRAME_DECODER_ADAPTER_H_