Profile https://event-loop-tests.glitch.me/count-anim.html in the performance tab.

The results seem misleading/confusing in a couple of ways.

Firstly, it seems like requestAnimationFrame runs really late in the frame, whereas I'd expect to see the JS related to rendering at the start of the frame, so it has the maximum amount of time to prepare the frame before displaying.

Secondly, the UI makes it look like the frame was delivered before any of the related JS has run. The screenshot showing "5" appears way to the left of the JS call that makes the DOM modification. I wouldn't expect to see the result of my DOM changes until the frame after.
 

Deleted: Screen Shot 2018-01-03 at 16.51.11.png 125 KB

	Screen Shot 2018-01-03 at 16.51.11.png 125 KB View Download