web-animations/web-animations-js — pull request #326 by mithro (2013-06-28 04:25:59+00:00)
Title: Fixing Issue #313 - at doesn't handle NaN gracefully.

Added more checks to the seconds argument for at(). Now makes sure;
* the number is positive or zero,
* the number isn't NaN,
* the number is finite.

See https://github.com/web-animations/web-animations-js/issues/313