It's misleading as in the rendering code we store pixel snapped coordinate values in float structures (e.g. FloatRect)
Created attachment 431796 [details] Patch
Committed r279056 (238976@main): <https://commits.webkit.org/238976@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 431796 [details].
<rdar://problem/79539712>