The current version of Firefox has this featured scrapped off. I know it has an infinitesimally low demand (if any at all) in the community. But this feature really helps those of us who have to enlarge, say, a video playing on a tiny section of the screen to get a better view of a word, phrase, etc, and get right back into typing without having to manually click on the text window to resume typing. Kindly return this feature. Thank you.