LineBox::isConsideredEmpty() is much cheaper
<rdar://problem/57454620>
Created attachment 384242 [details] Patch
Created attachment 384245 [details] Patch
Comment on attachment 384245 [details] Patch Clearing flags on attachment: 384245 Committed r252837: <https://trac.webkit.org/changeset/252837>
All reviewed patches have been landed. Closing bug.