Web views do not deal properly with their window's UIScene changing. If a Safari window is in the background for 1 minute, its UIScene will be detached and the window will get a new UIScene if the user later switches to this window. Our web views listen to UIScene notifications to determine their visibility and currently stop receiving visibility updates once the window’s UIScene has changed. This causes view freezes because our WebContent process does not know its view is visible and keeps its layer tree frozen.
<rdar://problem/55580699>
Created attachment 379304 [details] Patch
Comment on attachment 379304 [details] Patch Clearing flags on attachment: 379304 Committed r250187: <https://trac.webkit.org/changeset/250187>
All reviewed patches have been landed. Closing bug.