Pretending that just cause chrome doesn't come installed with the android open src project, means it isn't a "default" for android is silly; yes, google play services isn't required for android, but an overwhelming majority of android users will see chrome as the default for the OS. You claim they are making a choice, but for the average user it doesn't seem like much of a choice. It's easier for most android apps just to use chrome as an "in app browser", while the users have the option to use a different browser, most won't.