jquery/jquery — pull request #1403 by stsvilik (2013-10-24 04:21:32+00:00)
Title: Improve jQuery classes.js

This PR is targeting jQuery.addClass/jQuery.hasClass methods to improve performance using native Element.classList add/contains methods. For browsers that have Element.classList there will be a tangible performance boost. Here is the spec for classList https://developer.mozilla.org/en-US/docs/Web/API/Element.classList.

Performance test:
http://jsperf.com/jquery-classes-vs-classlist