Unlike most companies, when Google says “cloud”, they mean it. Compare Amazon’s cloud-computing service to Google’s. With the former, you essentially call up and configure one or more servers with the OS and specifications of your choice; but with Google’s App Engine, you don’t know anything about its hardware or operating system, because that no longer matters. It just runs the code you give it, and you don’t much care how. Similarly, Chrome is being built for a future where the ambient, omnipresent wireless Internet connects everything from clothes to computers to cars (which explains how their self-driving cars fits into their strategy) and it doesn’t much matter what OS any given device is running.