Created attachment 460651 [details] Xcode project showing the issue In our application (MacOS-application using WKWebView), we have an issue where after a certain magnification requestAnimationFrame-handlers are not called anymore (or very very rarely). I tried to strip down the issue and was able to reproduce it in a simple Cocoa-Application using a WKWebView which displays a web page. Steps to reproduce: * build and open the attached Xcode project * you see some elements and a red cell with an updating number in it * Click on the "zoom in"-button (and make sure you see the updating number) * Starting from a magnification of 3 (you can see the magnification in the lower right corner) the number stops updating * zoom out again and it starts again. the requestAnimationFrame handler is set in the viewer.html. If I use a simpler web page (only a one html with the same, or using a iframe it works as expected).
<rdar://problem/96447352>
Thanks for filing, this does not reproduce for me on macOS 12.5 beta 5 (21G5063a). I stopped zooming in around 25. Are you able to reproduce this on that build?
I can reproduce. You have to scroll sideways a little to get into the state where it stops animating.
The visibleRect passed to `FrameView::updateScriptedAnimationsAndTimersThrottlingState` is wrong. We should just change this code to use an internal IntersectionObserver.