[InputEvent] Add InputEvent with basic interface behind a flag

third_party/WebKit/Source/core/events/InputEvent.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 InputEvent_h
+#define InputEvent_h
+
+#include "core/events/InputEventInit.h"
+#include "core/events/UIEvent.h"
+
+namespace blink {
+
+class InputEvent final : public UIEvent {
+    DEFINE_WRAPPERTYPEINFO();
+
+public:
+    static PassRefPtrWillBeRawPtr<InputEvent> create()
+    {
+        return adoptRefWillBeNoop(new InputEvent);
+    }
+
+    static PassRefPtrWillBeRawPtr<InputEvent> create(const AtomicString& type, const InputEventInit& initializer)
+    {
+        return adoptRefWillBeNoop(new InputEvent(type, initializer));
+    }
+
+    bool isInputEvent() const override;
+
+    PassRefPtrWillBeRawPtr<EventDispatchMediator> createMediator() override;
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    InputEvent();
+    InputEvent(const AtomicString&, const InputEventInit&);
+};
+
+class InputEventDispatchMediator final : public EventDispatchMediator {
+public:
+    static PassRefPtrWillBeRawPtr<InputEventDispatchMediator> create(PassRefPtrWillBeRawPtr<InputEvent>);
+
+private:
+    explicit InputEventDispatchMediator(PassRefPtrWillBeRawPtr<InputEvent>);
+    InputEvent& event() const;
+    bool dispatchEvent(EventDispatcher&) const override;
+};
+
+DEFINE_EVENT_TYPE_CASTS(InputEvent);
+
+} // namespace blink
+
+#endif // InputEvent_h