The best path is to replace rows 479-480 with this row:
var ret = {x: node.offsetLeft, y: node.offsetTop, w: node.clientWidth, h: node.clientHeight };
(Tested on Firefox & Chromium)
Method getBoundingClientRect is used in other classes, so I think the problem persists if we use other parts of Dojo Toolkit.
A question to the Dojo Toolkit authors: is there a particular reason to use the getBoundingClientRect method instead of attributes?
Do you consider it appropriate to deprecate the use of getBoundingClientRect?