Fullscreen stack isn't part of the spec anymore; it's been changed to a more
generic version called Top Layer stack, which is being used by both full-screen
APIs and dialog elements.
This patch refactors it to Top Layer stack so that it can be reused for dialog
elements.
Top Layer stack spec: https://fullscreen.spec.whatwg.org/#new-stacking-layer
Since these are just interpreted comments, there's 0 impact on actual code.
This removes all lines that match /* vim: set(.*)tw=80: */ with S&R -- there are
a few others scattered around which will be removed manually in a second part.
Moonchild
FranklinDM
Matt A. Tobin