How does WPT respond to responsive layouts?

[pmeenan]

WPT runs the tests in a browser with the browser dimensions set to 1024x768 (viewport will be a bit smaller). There is a (not yet documented) script command that you can use for the Chrome and Firefox agents to specify a custom viewport size which is what Guy used in his testing for the bdconf presentation on responsive performance: http://www.slideshare.net/guypod/perform...ile-design

One quick warning from his presentation, display:none still causes the browser to load the resources so even though they aren't being displayed they will get loaded and take a performance hit. Steve Souders mentioned that he didn't think visibility:hidden had the same problem.