Once again, Google is stretching the definition of “evil” to find out what it can and can’t monetize. Users in the UK, Brazil and France now have the option to choose Sponsored Themes for their Gmail pages, including a very sweet Assassin’s Creed theme, pictured above. If the idea will fly, which we are guessing it will since every Mac fanboy out there will want to paint their Gmail with Apple logos, Google will look at rolling it out within the USA. While funky gaming and tech themes are sure to make Gmail sponsored themes popular, the potential for evil is still there; High School Musical 3 Gmail themes,…