Introduce the NotificationEvent object.

Source/modules/notifications/NotificationEvent.cpp

+// 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.
+
+#include "config.h"
+#include "modules/notifications/NotificationEvent.h"
+
+namespace blink {
+
+NotificationEventInit::NotificationEventInit()
+{
+}
+
+NotificationEvent::NotificationEvent()
+{
+}
+
+NotificationEvent::NotificationEvent(const AtomicString& type, const NotificationEventInit& initializer, WaitUntilObserver* observer)
+    : ExtendableEvent(type, initializer, observer)
+    , m_notification(initializer.notification)
+{
+}
+
+NotificationEvent::~NotificationEvent()
+{
+}
+
+const AtomicString& NotificationEvent::interfaceName() const
+{
+    return EventNames::NotificationEvent;
+}
+
+void NotificationEvent::trace(Visitor* visitor)
+{
+    visitor->trace(m_notification);
+    ExtendableEvent::trace(visitor);
+}
+
+} // namespace blink