"Continuous painting mode for paint profiling is now available in Chrome Canary. This article explains how you identify a problem in page painting time and how you can use this new tool to detect bottlenecks in painting performance. INVESTIGATING PAINTING TIME ON YOUR PAGE So you noticed that your page doesn't scroll smoothly. This is how you would start tackling the problem. For our example, we'll use the demo page Things We Left On The Moon by Dan Cederholm as our example. You open the Web Inspector, start a Timeline recording and scroll your page up and down. Then you look at the vertical timelines, that show you what happened in each frame." http://updates.html5rocks.com/2013/02/Profiling-Long-Paint-Times-with-DevTools-Continuous-Painting-Mode