Fullscreen in mobile browsers

Hi,

In desktop environments, the fullscreen icon actually goes full screen, removing window decorations (title and other bars, etc.).

It is clearly possible to do this in mobile browsers, because (e. g.) YouTube does it.

Why not let CVR do so? When I try to use Google Glass mode, it's annoying to have 20% of the screen real estate taken up by things I don't want to see. Of course, you'd have to leave in some way to exit GG mode.