Copyrights do not mean much here except that Google could license that code differently at some point, though the previous licenses are irrevocable so the "sold" Chrome would be the new main line, and Google's 90% of a browser fork under a new license could do something else. They'd certainly have to do some work to get it to be a browser again though because the 10% they cannot arbitrarily re-license is scattered around the codebase and some of it in critical parts of the system.