ScrollingTree::SwipeState.rubberBandsAtLeft etc are redundant with canRubberBand and unused.
<rdar://problem/105528909>
Pull request: https://github.com/WebKit/WebKit/pull/10189
Committed 260381@main (790fe9df8392): <https://commits.webkit.org/260381@main> Reviewed commits have been landed. Closing PR #10189 and removing active labels.