<op.ub6kqwejidj3kv@zcorpandell.linkoping.osa>
Current votes: None.
http://philip.html5.org/tests/canvas/suite/tests/2d.pattern.repeat.undefined.html
expects undefined to be stringified to "undefined" in
ctx.createPattern(canvas, undefined)
We recently changed our impl to treat undefined as null since we thought
it made sense to treat undefined and null the same.
It would be good if HTML 5 used WebIDL annotations for how to treat
undefined and null for createPattern (and probably other places).