The `font: message-box` rule inside common.css handles system fonts fine. See https://bugzilla.mozilla.org/show_bug.cgi?id=1190427#c46

As :ntim pointed out, font:message-box is already present on the page and it causes the system's UI font to be used. This bug is very noticeable on Windows, where we are now showing Arial when Segoe UI should be used.

Actually, in order to be be able to adjust the layout for different languages, this page includes localizable widths that are set so that content doesn't wrap. The right width depends on the font metrics. In the current setup, if localizers have already determined the right width for the old font, the effect with the new font might be incorrect I've checked that in English on OS X 10.9 the Tracking Protection state indicator is now on the next line. In this new situation where we have fonts with different metrics, we could maybe redefine the layout so that those widths are determined automatically, or at least the layout won't break - I'll try to see if this can be done while working on the redesign in bug 1192625, which we plan to uplift anyways. The alternative is just to rename the entities with the width so that localizers will check them a second time, similarly to what we did for the strings in bug 1192621, but it's unlikely we can uplift those changes to the Developer Edition channel.

Can this be uplifted to Aurora ?

(In reply to Tim Nguyen [:ntim] (mostly away until 26 August) from comment #5) > Can this be uplifted to Aurora ? Not until we've fixed the layout regressions this caused, which will be done in bug 1195270.

Comment on attachment 8646984 [details] [diff] [review] Patch Approval Request Comment [Feature/regressing bug #]: bug 1190427 [User impact if declined]: ugly styling for private browsing page on Windows [Describe test coverage new/current, TreeHerder]: visual change only [Risks and why]: none [String/UUID change made/needed]: none

This can be uplifted, but I'd like to see the outcome of the discussion in bug 1198287 first. We also have other style changes in the queue and it may be better to uplift everything in one block.

Comment on attachment 8646984 [details] [diff] [review] Patch Ready to be uplifted now that we have defined the approach in bug 1199644. Approval Request Comment [Feature/regressing bug #]: New about:privatebrowsing landing page [User impact if declined]: Sub-optimal design on a very visible page [Describe test coverage new/current, TreeHerder]: Landed on mozilla-central [Risks and why]: Limited to the page [String/UUID change made/needed]: None

Comment on attachment 8646984 [details] [diff] [review] Patch Improve the UX, taking it.

Verified fixed 42.0a2 (2015-09-10), 43.0a1 (2015-09-10) Win 7