I just watched the Google I/O session Jank Busters: Building Performant Web Apps where the speakers explained how to use the new \"Frames\" view in the Chrome web inspector
I'd recommend you use http://pagespeed.googlelabs.com
It will basically show you a complete detail of what happened when the page was being loaded so you know where to work on... (and I also think could miss certain information in some cases)
Also, you should do a memory profiling of the page to see how long some objects take to get loaded into the memory.