Why is this a problem ?
Now Google can (potentially) associate your browsing history with your identity, whereas before, any read of one's history would be anonymous.
There are many things that chrome is doing that are dubious, quasi legal
one thing they could be doing is a kind of reverse beacon or barium meal beacon where they generate a unique code and steganographically insert that as an overlay into images...you won't see the difference when your webpage loads the image, but then some javascript will send that image back to a server, and there you ahve a cross site tracking mechanism. This concept has been used in browser fingerprinting, but now that has evolved with html5 with the canvas tag which generates unique ids and sends that back in order to track your browser everywhere around the internet without needing cookies or websocket sessions or any other newer session mgmt mechanism