[1] Navigation Timing ( (2012-12-13 06:51:35 +09:00 版)) <http://www.w3.org/TR/2012/REC-navigation-timing-20121217/#sec-navigation-timing-interface>

[2] mark performance.timing as obsolete (igrigorik著, 2017-02-25 05:48:47 +09:00) <https://github.com/w3c/navigation-timing/commit/b9eee3958b66d268f06166b3887c51de1c7de627>