https://results.webkit.org/?suite=layout-tests&test=fast%2Flayoutformattingcontext%2Fsimple-absolute-positioned-replaced-inline-element-with-percentage-height.html
There's some weirdness going on with subframe layout timing. Let's just ignore subframes for now.
Committed r260378: <https://trac.webkit.org/changeset/260378>
<rdar://problem/62066731>