CSSOM getBoundingClientRect and device scaling

Has zoom/scaling been mentioned before? I am noticing that some
implementations will scale a page to a certain value. The method
getBoundingClientRect does not mention that the value returned should
be "de-scaled".
http://www.w3.org/TR/cssom-view/#dom-element-getboundingclientrect

Opera mini, in "Mobile view," scales the page. Fine, but then
getBoundingClientRect returns the actual pixel values, not "de-scaled"
values.

I did a brief write up on the problem I noticed with Opera Mini:
http://my.opera.com/dhtmlkitchen/blog/show.dml/4359747

Should the spec mention what should happen when the device rescales values?

Garrett