I don't really like this.

I think this should fit in a rewritten showMessageError using my suggestion in https://github.com/mozilla-b2g/gaia/pull/13064#issuecomment-27877748

Maybe you can do the rewriting part so that the contributor in bug 917954 will only change the text label? Or just steal bug 917954 because there is not much progress since a few days, and if you need it for this here, it's maybe not a mentoring bug anymore.

What do you think?