Calling webkitRequestFullscreen() on an element flowed in regions will put the entire document in full screen (as if document.webkitRequestFullscreen() was called).
While this specific aspect is not clearly specced, this is counter to what happens when making full-screen an element fragmented through columns and also counter-intuitive.
Also, if the element is fragmented through regions, there are also some layout/rendering artifacts in the form of black margins before and after the element.
1. Open attached file
2. Click the button
Expected: Page goes full-screen and only the second paragraph with green border is visible
Actual: Page goes full-screen but with all the document being visible. Also, there is a black margin/border before and after the green paragraph.
Created attachment 214737 [details]
HTML file highlighting the problem
Created Blink counter-part over at https://code.google.com/p/chromium/issues/detail?id=309639
Not reproducible in nightly 167020