Some basic support for this landed in WebKit recently: http://peter.sh/2012/01/css-selector-profiler-source-mapping-and-software-rendering/ http://peter.sh/2012

Some basic support for this landed in WebKit recently: http://peter.sh/2012/01/css-selector-profiler-source-mapping-and-software-rendering/ http://peter.sh/2012/01/css-selector-profiler-source-mapping... I'd like to see this hooked up to the Rails asset pipeline!