Reported by jteh on 2010-04-21 07:56
If aria-describedby is set on an ARIA dialog, Mozilla will expose this as the description. We should use this in preference to our own getDialogText code.

Test cases: tests 2 and 3 at http://www.accessibleculture.org/testing/aria/alertdialog/

Considerations:

• Do we somehow stop our Dialog behavior from being used or do we tweak the Dialog behavior to not bother with getDialogText if description is valid?
• Are there any cases where other dialogs provide a useless description? If so, we don't want to do this for all dialogs, only Mozilla ones.