Drop m.redraw.sync() from v3

[dead-claudia]

redraw.sync() was previously added because iOS used to refuse to autoplay <audio autoplay> and <video autoplay> elements unless they were added to the DOM during the execution of a user interaction event listener. WebKit relaxed this for silent videos, but nothing in that article indicates anything else changed.

From my own recent testing on iOS, their blocking mechanism changed from an "is this synchronous" check to a simple 5 second timer after user interaction before autoplay fails - as long as less than 5 seconds have elapsed, no matter where you are in the code, it's fair game now. This timer starts before the handler (came to about 50ms or so on my phone), but is not checked until after the handler executes.

Since it no longer matters whether things are done synchronously or not, it's safe to do that kind of thing in an animation frame callback now. And because of it, redraw.sync() is no longer needed.

[JAForbes]

I'm in favour, I've personally never used it in production.