Comment 3 for bug 828092

There was no plan to develop a custom UI. While mocking up the new USC appearance, one of our visual designers experimented with a style for toolbars that might have become the standard for Ambiance. It turned out not to be, but the mockup wasn't updated before it was implemented.

Thanks for the pointer to the primary-toolbar class. I agree we should use it, but it's not clear to me that using it would fix any of the issues I described in this bug report. I've reported bug 828762 on the inconsistent appearance of the navigation bar as a whole.