[css3-animations] CSSKeyframeRule and rules with multiple keys

http://dev.w3.org/csswg/css3-animations/#DOM-CSSKeyframeRule says:
  # The CSSKeyframeRule interface represents the style rule for a
  # single key.
and goes on to describe the keyText attribute as representing a
single floating point number.

However, keyframe rules can have selectors with multiple numbers,
e.g.:
  25%, 75% { color: green }
What should such a rule return for keyText?

Also, what should happen when setting keyText?  For example, which
of the following should work:
  rule.keyText = "0.25";
  rule.keyText = "0.25, 0.75";
  rule.keyText = "25%";
  rule.keyText = "25%, 75%";

(It would seem a little more consistent with style rules if keyText
aligned with selectorText and actually represented the text of the
selector, e.g., "25%, 75%".)

-David

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/