[SafdarIqbal]

There is no way to get notifications if you're using Firefox or Safari.

[abraham]

A missing feature != ban. Plus I'm pretty sure you are wrong.

"This setting applies to all Hangouts notifications from Gmail, Google+ and the Chrome extension on the same desktop computer."

Gmail and Google+ are both supported in all major browsers.

https://support.google.com/hangouts/answer/3111923