This extension shows the time it takes for a web page to reach 60fps
Just load any page with the extension active and when the page reaches a constant 50-60fps over a full second it will then display the time it took to reach this constant frame rate in seconds. Only 5 digits can be displayed so accuracy may be lost for really slow pages.
Clicking the icon will refresh the page.
Some pages (such as chrome://extensions ) can not be scripted so the timing will never show up.