Notifications are concise, unobtrusive messages that appear in the top-right corner of the screen, alerting OSX users about a new message or a completed task. Safari users can allow websites to display banners and alerts in Notification Center because Apple has been using the Apple Push Notification Service for some time now. There are two notifications, local vs web site push notifications. Local notifications are controlled entirely by JavaScript, the user must have a website open in a Safari window (or tab) for your notification to appear. Safari can be minimized or hidden, or a website could be loaded in an inactive tab, but it must be open to run the JavaScript that creates the notification. You can view the local vs web site notifications below:
Google is working on supporting OS X’s native push notifications in Chrome, instead of the browser having to use its own notification system, according to appleinsider, and reports, “Google’s existing notification system lets websites send alerts even once a person has left a webpage, as long as they have user permission. Support for native notifications should weave those messages into OS X’s Notification Center, and respect global settings, including the Do Not Disturb mode.”
The pre-release is available, however, this Chromium Developer Discussion says it is not stable yet. There is little indication when the stable version will be released.