Introduce the NotificationEvent object.

Source/modules/notifications/NotificationEvent.h

+// Copyright 2014 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 NotificationEvent_h
+#define NotificationEvent_h
+
+#include "modules/EventModules.h"
+#include "modules/notifications/Notification.h"
+#include "modules/serviceworkers/ExtendableEvent.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+struct NotificationEventInit : public EventInit {
+    NotificationEventInit();
+
+    Member<Notification> notification;
+};
+
+class NotificationEvent final : public ExtendableEvent {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    static PassRefPtrWillBeRawPtr<NotificationEvent> create()
+    {
+        return adoptRefWillBeNoop(new NotificationEvent);
+    }
+    static PassRefPtrWillBeRawPtr<NotificationEvent> create(const AtomicString& type, const NotificationEventInit& initializer, WaitUntilObserver* observer)
+    {
+        return adoptRefWillBeNoop(new NotificationEvent(type, initializer, observer));
+    }
+
+    ~NotificationEvent() override;
+
+    Notification* notification() const { return m_notification.get(); }
+
+    const AtomicString& interfaceName() const override;
+
+    void trace(Visitor*) override;
+
+private:
+    NotificationEvent();
+    NotificationEvent(const AtomicString& type, const NotificationEventInit&, WaitUntilObserver*);
+
+    PersistentWillBeMember<Notification> m_notification;
+};
+
+} // namespace blink
+
+#endif // NotificationEvent_h