Firefox built an visualization browser add-on called Lightbeam. Determined to unearth all the services tracking you as you visit sites throughout your day, Lightbeam is an exercise in what you can glean from the sites tracking you.
While this is purely speculated from the front-end code, there is even more data getting shared in the back-end. This is a great first step towards exposing how the web works underneath us. Unfortunately there is no Chrome extension.