Apply the scroll delta in the "began" wheel event
Created attachment 447903 [details] Patch
Created attachment 447910 [details] Patch
Created attachment 447922 [details] Patch
Committed r287431 (245566@main): <https://commits.webkit.org/245566@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 447922 [details].
<rdar://problem/86896600>