http://developer.chrome.com/extensions/notifications.html
只有当用户的鼠标不在正在显示的通知窗口上方时,我才需要在 X 秒后关闭通知窗口。
var notification = webkitNotifications.createNotification(
'icon.png',
'Notification titile',
'Notification body text'
);
notification.show();
// TODO: Close notification window only if user's mouse is not over it
setTimeout(function() { notification.cancel() }, 10000);