jquery/jquery-mobile — pull request #3849 by pikotea (2012-03-19 12:54:06+00:00)
Title: replace the -9999px hack of "ui-hide-label" and "ui-hidden-accessible".

Better performance for mobile.
http://www.zeldman.com/2012/03/01/replacing-the-9999px-hack-new-image-replacement/