Chrome OS team is working on a new API for cloud storage services to act like another drive within the Files app. In other words, make them work just like Google Drive on your Chromebook. I like the way Dropbox integrates with my computer and Android phone. The experience is seamless. When this API is ready, I am assuming that Chrome OS will be ready to provide that experience with any cloud storage service that you would like to use.
Here is how it might look like, image courtesy of OMG Chrome.