There are ARIA attributes, e.g. ariaControlsElements, which refer to a
list of elements by their ID. For example:
<div aria-controls="item1 item2">
The div.ariaControlsElements attribute would be a list of elements whose
ID matches the values in the aria-controls attribute.
The property-reflection.html test was partially split into a second file
recently, property-reflection-imperative-setup.html. Let's re-import to
ensure we have the latest. See:
https://github.com/web-platform-tests/wpt/commit/2518df1
Let's simply reinsert the element respecting it's new position in the
DOM tree, instead of crashing.
Fixes regression in WPT tests caused by introducion of cache for
getElementById().
