Bug 234913

Created attachment 448469 [details] repo for issue above Steps to repo 1) Download the zip file, unzip, serve the file (npx servez), open test.html in Safari on iOS (http://<your-mac-ip-address>:8080/test.html) 2) Switch from Safari to the home screen, wait a few seconds 3) Switch back to Safari What should happen: you should see some text "Hello World" and "Round 1" animating as well as a count counting up What happens instead: No animation happens Here's a video of it happening ( https://www.youtube.com/watch?v=FftyV0iYtJw ) Notice after going back to Safari the counter is no longer updating If you go change line 115 from "RobotoBold" to "monospace" and follow the steps above (kill the tab first), you'll see with "monospace" the animation does not stop. HEre's a video of it working with "monospace" ( https://www.youtube.com/watch?v=g8rKxxayZHw ). notice after going back to Safari the counter is still updating The sample uses `setInterval` (yea, I know, it should use rAF, the code that provoked this is probably > 10 year old) If you use the remote debugger, after restoring safari, and put a breakpoint on `draw` you'll see it only gets called once every several seconds and though it is calling drawing functions none of them are affecting the canvas. Further, often you can't even refresh the tab in Safari. You can kill the tab and start a new one though. My understanding is this worked on iOS 14 (don't have iOS 14 to test but the person that found the bug originally said their site broke when they upgraded to iOS 15). This is the small repo.