jquery/jquery — pull request #1560 by ckosmowski (2014-04-14 14:08:00+00:00)
Title: Performance Improvement. Change the order of conditions in the css hooks code. 

Now the new cleaner Pull request:

This improves the performance of the css hooks code by preventing some reflows. (Reading elem.offsetWidth will cause a reflow everytime the condition is tested).

refs http://bugs.jquery.com/ticket/14979