https://wpt.fyi/results/css/css-contain?label=master&label=experimental&product=chrome&product=firefox&product=safari&aligned&view=interop&q=counter-scoping
<rdar://problem/114098617>
counter-scoping-002.html fails due to the lack of counter-set support.
These two tests are about creating implicit counters at the contain: style boundary. contain-scoping-004.html is a different issue that I'll split out.