There are so many great articles out there regarding the performance of web browsers and rendering. This is an ever growing collection of links and to articles and information covering the topic. Feel free to ping me with any articles you have found so that I can add them to this list.
Avoiding Unnecessary Paints – http://www.html5rocks.com/en/tutorials/speed/unnecessary-paints/
Performance Profiling - https://developers.google.com/chrome-developer-tools/docs/using-timeline