Add HpackDecoderState and HpackDecoderListener.

net/http2/hpack/decoder/hpack_decoder_listener.cc

Index: net/http2/hpack/decoder/hpack_decoder_listener.cc
diff --git a/net/http2/hpack/decoder/hpack_decoder_listener.cc b/net/http2/hpack/decoder/hpack_decoder_listener.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8bb0e47e9a2c0e9ca89d7860ef5e03820d81d33d
--- /dev/null
+++ b/net/http2/hpack/decoder/hpack_decoder_listener.cc
@@ -0,0 +1,32 @@
+// 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_decoder_listener.h"
+
+using base::StringPiece;
+
+namespace net {
+
+HpackDecoderListener::HpackDecoderListener() {}
+HpackDecoderListener::~HpackDecoderListener() {}
+
+HpackDecoderNoOpListener::HpackDecoderNoOpListener() {}
+HpackDecoderNoOpListener::~HpackDecoderNoOpListener() {}
+
+void HpackDecoderNoOpListener::OnHeaderListStart() {}
+void HpackDecoderNoOpListener::OnHeader(HpackEntryType entry_type,
+                                        const HpackString& name,
+                                        const HpackString& value) {}
+void HpackDecoderNoOpListener::OnHeaderListEnd() {}
+void HpackDecoderNoOpListener::OnHeaderErrorDetected(
+    StringPiece error_message) {}
+
+// static
+HpackDecoderNoOpListener* HpackDecoderNoOpListener::NoOpListener() {
+  static HpackDecoderNoOpListener* static_instance =
+      new HpackDecoderNoOpListener();
+  return static_instance;
+}
+
+}  // namespace net