This is in preparation for incremental line layout
Created attachment 436640 [details] Patch
Committed r281714 (241058@main): <https://commits.webkit.org/241058@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 436640 [details].
<rdar://problem/82450099>
*** Bug 229299 has been marked as a duplicate of this bug. ***