true html5 fullscreen

[Antoine Martin]

When an application requests to go fullscreen, we should make the browser fullscreen too, not just the window within the browser.

​Element.requestFullScreen

[Antoine Martin]

19570 adds a fullscreen toggle to the top bar.

This is as good as it is going to get: we can't trigger fullscreen when an application requests it because we can only request fullscreen in response to user events. (and registering a catch all keyboard / mouse event handler for this is yukky).
We can't bring attention to the fullscreen icon either because we the window is about to cover it.