IFC should provide the line spanning inline boxes in the run list so that the integration (or other FC) code should not need to looking into the line box to extract the inline boxes.
Created attachment 433753 [details] Patch
Created attachment 433754 [details] Patch
<rdar://problem/81077420>
Created attachment 436342 [details] Patch
Created attachment 436343 [details] Patch
Created attachment 436402 [details] Patch
Committed r281575 (240939@main): <https://commits.webkit.org/240939@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 436402 [details].