[cssom-view] add height/width to ClientRect?

Should we extend ClientRect with a height and width attribute? They are  
somewhat redundant as you can calculate height by bottom-top and width by  
right-left, but having them directly available is convenient for authors  
and very low cost for implementors.

Thoughts?


-- 
Anne van Kesteren
<http://annevankesteren.nl/>
<http://www.opera.com/>