RE: [css3-animations] CSSKeyframesRule.findRule()

[Tab Atkins Jr.:]
> 
> If we're renaming the method, we don't have to worry about back-compat in
> the arguments. ^_^
> 
Compat means you can't remove it and our keyframe rule cascade resolution means
we still have to define what findRule() returns; given that we no longer
drop duplicate rules for a given selector value we can't just return the first
or last rule.