[UI-side compositing] Remove dereference in RemoteScrollingTreeMac::handleWheelEventPhase
<rdar://problem/106420122>
Pull request: https://github.com/WebKit/WebKit/pull/11238
Committed 261452@main (bf3c4d5c6bec): <https://commits.webkit.org/261452@main> Reviewed commits have been landed. Closing PR #11238 and removing active labels.