Make Notification override hasPendingActivity() to prolong its lifetime while async op is running

Source/modules/notifications/Notification.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 53 matching lines @@
     REFCOUNTED_EVENT_TARGET(Notification);
 public:
     Notification();
 #if ENABLE(LEGACY_NOTIFICATIONS)
     static PassRefPtr<Notification> create(const String& title, const String& body, const String& iconURI, ExecutionContext*, ExceptionState&, PassRefPtr<NotificationCenter> provider);
 #endif
     static PassRefPtr<Notification> create(ExecutionContext*, const String& title, const Dictionary& options);
 
     virtual ~Notification();
 
+    // Calling show() may start asynchronous operation. If this object has
+    // a V8 wrapper, hasPendingActivity() prevents the wrapper from being
+    // collected while m_state is Showing, and so this instance stays alive
+    // until the operation completes. Otherwise, you need to hold a ref on this
+    // instance until the operation completes.
     void show();
 #if ENABLE(LEGACY_NOTIFICATIONS)
     void cancel() { close(); }
 #endif
     void close();
 
     String title() const { return m_title; }
     String dir() const { return m_direction; }
     String lang() const { return m_lang; }
     String body() const { return m_body; }
@@ skipping 25 matching lines @@
     void dispatchShowEvent();
     void dispatchErrorEvent();
     void dispatchCloseEvent();
 
     // EventTarget interface
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ExecutionContext* executionContext() const OVERRIDE { return ActiveDOMObject::executionContext(); }
     virtual bool dispatchEvent(PassRefPtr<Event>) OVERRIDE;
 
     // ActiveDOMObject interface
+    // Override to prevent this from being collected when in Showing state.
+    virtual bool hasPendingActivity() const OVERRIDE;
     virtual void stop() OVERRIDE;
 
     static const String& permission(ExecutionContext*);
     static const String& permissionString(NotificationClient::Permission);
     static void requestPermission(ExecutionContext*, PassRefPtr<NotificationPermissionCallback> = 0);
 
 private:
 #if ENABLE(LEGACY_NOTIFICATIONS)
     Notification(const String& title, const String& body, const String& iconURI, ExecutionContext*, ExceptionState&, PassRefPtr<NotificationCenter>);
 #endif
     Notification(ExecutionContext*, const String& title);
 
-    void finalize();
-
     void setLang(const String& lang) { m_lang = lang; }
     void setBody(const String& body) { m_body = body; }
     void setIcon(const KURL& url) { m_icon = url; }
 
     void showSoon();
 
     // Text notifications.
     KURL m_icon;
     String m_title;
     String m_body;
@@ skipping 11 matching lines @@
     NotificationState m_state;
 
     NotificationClient* m_notificationClient;
 
     OwnPtr<AsyncMethodRunner<Notification> > m_asyncRunner;
 };
 
 } // namespace WebCore
 
 #endif // Notifications_h