(This is for after T34284)
https://developer.chrome.com/apps/notifications
Use the chrome.notifications API to create rich notifications using templates and show these notifications to users in the system tray.
https://developer.mozilla.org/en-US/docs/Web/API/notification
The Notification interface of the Notifications API is used to configure and display desktop notifications to the user.
See also T115264: Notification panel: Control notification volume