Created attachment 8629628 [details] [diff] [review]
This is a requirement for Mail Summaries to land in Thunderbird, but it'd also be useful for any other add-ons that want to put some HTML inside the account central pane. The patch is about as simple as it gets. :)
Maybe there's an argument for delaying this until the account summaries finally land, but this makes my life easier for maintaining Mail Summaries as an add-on, too. Overall, I think it's a positive change, although not super-useful until Mail Summaries merges.
Bug 1180462 - Let Account Central show HTML tooltips. r=mconley