Bug
1547759 - Add a flag to allow FinishReflowChild to handle relative positioning, and convert the caller for which this makes sense. r=jfkthame
Note that this changes the writing mode used for the SetSize call from
the parent's to the child's. (This controls what position is kept
constant.) I don't think this changes behavior at all, since there is
(for this caller) a SetRect call just below.
Differential Revision: https://phabricator.services.mozilla.com/D40566
--HG--
extra : moz-landing-system : lando