[css3-transitions] What happens when property specified multiple times for 'transition-property' ?

The http://dev.w3.org/csswg/css3-transitions/ specification should
define what happens when the same property is specified multiple
times for 'transition-property'.  I think reasonable choices (in
order of my preference) are:
  (1) the last one wins
  (2) the first one wins
  (3) it's a syntax error

My preference between (1) and (2) is weak, and I'd be happy to
follow what existing implementations have done.

I'd note that if we allow shorthands for 'transition-property', we
also need to define the behavior when a property is specified once
as a longhand and once within a shorthand, e.g.:

  transition: background-color 5s, background 3s;

-David

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