RE: Shadows vs. layout

Re: outlines should not affect scroll dimensions.

I added a test case to http://hpaa.com/firefox/shadow.htm. Opera and
Safari/Chrome render outlines per spec, with no effect on scrollWidth. With
Firefox, however, the outline affects scrollWidth. I don't have IE8
installed.

Maybe it would be helpful to imagine 'effects layers' above and below each
element. Overflow has no meaning on effects layers. Like the canvas, they
extend infinitely in 2 dimensions and clip only to the viewport.

David Perrell