We can avoid expensive repaints of the selection tiled layer most of the time if we unparent this layer when there is no selection to paint.
<rdar://128971102>
Pull request: https://github.com/WebKit/WebKit/pull/29347
Committed 279560@main (af2b37e3e31f): <https://commits.webkit.org/279560@main> Reviewed commits have been landed. Closing PR #29347 and removing active labels.