Visible is enough. It does not have to be focused. It can mostly also be covered by other (browser) windows, but if it is minimized or in another tab, it gets t

Visible is enough. It does not have to be focused. It can mostly also be covered by other (browser) windows, but if it is minimized or in another tab, it gets throttled. That hit me a few times, but ads and malware ruined that for everyone. (and there is no simple permission dialog possible, where you ask the user to allow it)