web-animations/web-animations-next — pull request #225 by samthor (2014-11-13 07:20:03+00:00)
Title: check for NaN in calculateTransformedTime

Otherwise, the cubic interpolator (possibly others?) will infinite loop because it never satisfies this condition-

if (Math.abs(x - xEst) < 0.001) {

where `x` is `NaN`. `NaN - number == NaN`, `NaN < 0.001 == false`.