In Firefox I would like to pass to another tab while an ad is playing
in the current tab, but the pesky thing will pause when its tab loses the focus.
I would like to trick the ad to believe that it still has the focus,
for it to keep on playing so I don't have to wait for it to finish.
How can I make a Firefox tab falsely believe that it still has the focus ?
You can make the assumption that the page is using techniques described here.
window.onblur are probably used. I don't remember where exactly I needed this when I asked the question; this is not necessarily used to trick ads. I'm looking for a generic solution.