[whatwg] api for fullscreen()

[Michael Dale]

It would be really nice if the html5 spec supported a javascript call to 
set a target window to fullscreen. The browser would then issue a 
security warning at the top of the page (similar to pop-ups) and then 
the user could grant that domain permission to go full-screen.

This is especially useful for video tag interfaces. For example we could 
expose a themed full-screen button in the player that is the equivalent 
of hitting f11 in Firefox. The video element container could be set to 
width:100% height:100% in the target window retaining support for 
javascript driven DOM overlays like timed text, temporal click spaces, 
site themed specific video controls sliding in at the bottom when the 
user moves the mouse, exiting full screen on

This is distinct from the browser providing a full-screen on the video 
element because we retain DOM overlays and javascript bindings, allowing 
sites to theme and customize the full-player experience.

To reiterate this is a separates spec request from the full-screen 
support for video element rather it just applies to exposing a 
permission system for JavaScript to control a browser "window" being 
full screen.

--michael