[UI-side compositing] Add logging for painting new tile for ScrollPerf
<rdar://problem/106775893>
Pull request: https://github.com/WebKit/WebKit/pull/11627
Committed 262258@main (d4f1d3db3f61): <https://commits.webkit.org/262258@main> Reviewed commits have been landed. Closing PR #11627 and removing active labels.