Should we be using or avoiding window.confirm()/alert/prompt/modal dialogs?

[Andrew Sutherland]

The system app provides a window.confirm() implementation.
Unfortunately, it currently is not actually using the shared/building
blocks confirm.css so it doesn't meet Visual Design guidelines and has
wrapping problem, etc. See
https://bugzilla.mozilla.org/show_bug.cgi?id=818047#c5

In the e-mail app we are currently largely displaying confirmation
dialogs by just using confirm.css and throwing up an appropriate DOM
hierarchy ourselves, but we have 2 window.confirm() calls.

Should we/other apps be avoiding window.confirm(), or should we be
trying to use it? MDN has very little or nothing to say on
https://developer.mozilla.org/en-US/docs/DOM/window.alert and friends
about re-entrancy of JS within the page in single-process Firefox, let
alone multi-process B2G where we might not bothering spinning nested
event loops, etc.

Andrew