Firebug or chrome “slow play” or “animated step into”?

Question

I inherited a large (many files, 20,000+ lines) proprietary front-end/JavaScript library at work. Is there a Firebug or Chrome feature, dev tool or plug-in that would allow me to "slow play" or automatically and visually step-into the loading/initialization of this large library to help me see how it works and learn it? Normally, it obviously loads quickly and I can't see anything; I could put a break point or a few in the script and "step into" through it, but that is too slow. I just had the idea that a dev tool that visually "played" the executing scripts, say, stepping into a line once every tenth of a second could be valuable. Is there such a thing?

Answer 1

As far as I know there is currently no dev tool offering such feature.

For Firebug there's at least a request for this . You may want to add your use case there and provide a test case with steps for how you imagine that feature should work exactly.