Calls to setTimeout(..., 0) were previously clamped to a 1 ms timeout, instead of resulting in a callback as soon as possible. This clamping is being removed. To get the old behavior, use setTimeout(..., 1) instead.
This is intent to remove 1ms clamping from JavaScript setTimeout() with a timeout of 0ms, which is not specified in HTML spec and Safari doesn't enforce this clamping. Removing this clamping results in performance improvement on Speedometer.