Chrome is a platform for client-side Google services.
As the article says, the web browser is the most obvious component, but it also includes Google Cloud Print [0], Google Talk/Hangouts [1], Google Earth [2], Google Music [3], Gmail Offline [4], etc.
In some sense it's the spiritual successor to Google Desktop [5], which used to fill a similar role.
[0] https://en.wikipedia.org/wiki/Google_Cloud_Print
[1] https://gsuiteupdates.googleblog.com/2014/10/notification-re...
[2] visit https://www.google.com/earth/ in a browser other than Chrome
[3] https://support.google.com/googleplaymusic/answer/4627259