A couple of specification issues. 1) WebIDL for KeyframeEffect (http://w3c.github.io/web-animations/#the-keyframeeffect-interfaces) contains the following
// Mutable additions to KeyframeEffectReadonly interface inherit attribute DOMString spacing; void setFrames (object frames); I think that spacing attribute is not an addition to KeyframeEffectReadonly interface but rather mutable override of its member 2) KeyframeEffectReadonly.clone() returns KeyframeEffect instance. It should return KeyframeEffectReadonly instance. Otherwise this method should be moved to KeyframeEffect interface 3) Definition of AnimationTimingReadonly.fill attribute (http://w3c.github.io/web-animations/#dom-animationtimingreadonly-fill) is the following: - If the animation node to which the fill mode is being is applied is an animation, Use none as the fill mode. - Otherwise, Use both as the fill mode. On level 1 we define only one type of animation node - animation. Does it makes sense describe fill behavior for non animation nodes here? Thank you, Sergey G. Grekhov