and not const ContainerBox* Layout tree is immutable during layout, so it's guaranteed to have a valid containing block.
<rdar://problem/60732278>
Created attachment 394188 [details] Patch
Comment on attachment 394188 [details] Patch nice
Committed r258819: <https://trac.webkit.org/changeset/258819> All reviewed patches have been landed. Closing bug and clearing flags on attachment 394188 [details].