Add a blink InterfaceRegistry.

third_party/WebKit/Source/platform/exported/InterfaceRegistry.cpp

+// 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 "public/platform/InterfaceRegistry.h"
+
+#include "wtf/StdLibExtras.h"
+
+namespace blink {
+namespace {
+
+class EmptyInterfaceRegistry : public InterfaceRegistry {
+  void addInterface(const char* name,
+                    const InterfaceFactory& factory) override {}
+};
+
+}  // namespace
+
+InterfaceRegistry* InterfaceRegistry::getEmptyInterfaceRegistry() {
+  DEFINE_STATIC_LOCAL(EmptyInterfaceRegistry, emptyInterfaceRegistry, ());
+  return &emptyInterfaceRegistry;
+}
+
+}  // namespace blink