Although I never saw gmail has the popup notification, but I really hope when I closed the browser, it somehow still will popup the notification, that will be super crazy.
I am not sure if OSX support web server push notification to the "Notification center" because, iOS is doing so.
Web Notification is only available when you have page opened.
There are many solutions of pubsub in web server, such as push notification in iOS. So once your web server can push messages to the client, you can send the notification to 'Notification Center'.
Google Chrome has added an option lately to keep running after you close the browser window. The option is called "Continue running background apps when Google Chrome is closed." If you click the wrench icon, there would be an option to View Background Pages.
@sp332 Thanks for the info. Yup, if you install the offline Gmail, it will still check in the background when Chrome is closed. This background feature is only available to Chrome apps or extensions but not to the web pages.
I am not sure if OSX support web server push notification to the "Notification center" because, iOS is doing so.