The client of WKWebView will provide CALayers for the page banners. WKWebView will add them to its layer tree. Their heights will adjust the page frameRect and the page contentSize. Mini browser will create two dummy CALayers and call the WKWebView SPI when the Setting: "Reserve Space For Banners" is checked.
rdar://101040993
Pull request: https://github.com/WebKit/WebKit/pull/11215
Committed 261597@main (16b186659066): <https://commits.webkit.org/261597@main> Reviewed commits have been landed. Closing PR #11215 and removing active labels.