Screen resolution user agent for Google Chrome

Hello, I need a google chrome extension that will change the screen resolution user agent so the counter trackers like statcounter dot com will show random screen resolutions every x number of seconds. I understand that I need to refresh the page visited to have the new user agent recorded by the site visited. i.e. Change screen resolution user agent every 15 seconds. I should be able to specify the resolutions of the screen that should be rotated in a small list or copy paste into your extension. I already use user agents to replace the language and browser but I have not found any to replace the screen resolution. Thanks!