Update classList.js polyfill to 1.2.20180112 with use of CDN
Updates classList.js polyfill to 1.2.20180112 with use of CDN.
Upstream diff between 1.1.20170427 and 1.2.20180112: https://github.com/eligrey/classList.js/compare/1.1.20170427...1.2.20180112
The polyfill was originally introduced in !182 (merged) 3 years ago (2018-01).
Edited by Takuya Noguchi