descendants is not accurate enough since we lay out only a subset of the out-of-flow descendant, the set that belongs to this formatting context.
<div style="float: left"><div style="position: absolute"><div style="position: absolute"></div></div></div>
<- the float's block formatting context will not lay out the inner absolutely position descendant. that's the outer abs pos box's responsibility.
Created attachment 375697 [details]
Comment on attachment 375697 [details]
Clearing flags on attachment: 375697
Committed r248365: <https://trac.webkit.org/changeset/248365>
All reviewed patches have been landed. Closing bug.