[InputEvent] Add InputEvent with basic interface behind a flag

third_party/WebKit/Source/core/events/InputEvent.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 "core/events/InputEvent.h"
+
+#include "core/events/EventDispatcher.h"
+
+namespace blink {
+
+InputEvent::InputEvent()
+{
+}
+
+InputEvent::InputEvent(const AtomicString& type, const InputEventInit& initializer)
+    : UIEvent(type, initializer)
+{
+}
+
+PassRefPtrWillBeRawPtr<EventDispatchMediator> InputEvent::createMediator()
+{
+    return InputEventDispatchMediator::create(this);
+}
+
+bool InputEvent::isInputEvent() const
+{
+    return true;
+}
+
+DEFINE_TRACE(InputEvent)
+{
+    UIEvent::trace(visitor);
+}
+
+PassRefPtrWillBeRawPtr<InputEventDispatchMediator> InputEventDispatchMediator::create(PassRefPtrWillBeRawPtr<InputEvent> inputEvent)
+{
+    return adoptRefWillBeNoop(new InputEventDispatchMediator(inputEvent));
+}
+
+InputEventDispatchMediator::InputEventDispatchMediator(PassRefPtrWillBeRawPtr<InputEvent> inputEvent)
+    : EventDispatchMediator(inputEvent)
+{
+}
+
+InputEvent& InputEventDispatchMediator::event() const
+{
+    return toInputEvent(EventDispatchMediator::event());
+}
+
+bool InputEventDispatchMediator::dispatchEvent(EventDispatcher& dispatcher) const
+{
+    return EventDispatchMediator::dispatchEvent(dispatcher) && !event().defaultHandled();
+}
+
+} // namespace blink