I was looking at the Toolbar.png files containing the new icons for the toolbar buttons in Australis, and I noticed that the windows Toolbar.png files have a secondary and tertiary row of icons that, as far as I can tell, are never used. I'm extrapolating from the Mac icons implementations that these were supposed to be hover status icons (and the third row for pressed/open status I guess). My question is, why are these included in the files if they are not used? Were they kept as a "just in case"? Is there a bug where these are being discussed that I can track? The reason for my question is I'm migrating my add-on to be used in Australis builds, and trying to integrate it visually as best as I can, making my custom icons colors match the default ones; and I'm unsure if I should be creating hover status icons for windows or not.

This is becaus a metro-related bug added these. Before, the file looked like this: http://hg.mozilla.org/mozilla-central/raw-file/81ce85168be1/browser/themes/windows/Toolbar.png I don't understand. Stephen, was this intentional? I don't see any discussion about this on the bug so I do not understand why these icons were added without using them or filing a followup or... well.

Actually, scratch that, this is just a dupe of bug 944781.