The Aero theme has only one icon size and it makes no sense to allow to switch to big icons. This would only make Add-on icons blurry when in big icon mode and they are forced to a 16px * 16px icon size.
Created attachment 623418 [details] [diff] [review]
I copied the styles to force the small icons from Bug 709799.
Additionally I changed in messageHeaders.css files of all themes the inefficient selectors to hide some elements in customize window to IDs (available since Bug 736738).
Comment on attachment 623418 [details] [diff] [review]
I like it! r=me!