Known issues:
* Display list optimization can sometimes optimize out elements that
should be shown. This affects the Enyo demo.
* The `overflow: scroll` container doesn't clip the inner layer properly
when borders, border radius, etc. are present.
* `overflow-x: scroll` and `overflow-y: scroll` don't work individually;
elements are scrolled all at once.
Note that multiple layers per stacking context aren't needed for the Enyo demo; rather the issue is that the height of the main area is being calculated incorrectly. (It looks like JS is measuring the height and poking in an explicit value that is too tall.)
r? @glennw
Source-Repo: https://github.com/servo/servo
Source-Revision: b05b02e11fb849e1f0153d009d8fcf0501ace8dc
03469bd0d3