Right now we invalidate more than necessary when doing regions layout. Check for invalidation only after the height of the region is fully computed.
Created attachment 230912 [details] Patch
Comment on attachment 230912 [details] Patch r=me
Comment on attachment 230912 [details] Patch Clearing flags on attachment: 230912 Committed r168363: <http://trac.webkit.org/changeset/168363>
All reviewed patches have been landed. Closing bug.