A brand new Chrome OS app is now available that makes use of newer APIs on the platform to add support for Dropbox to your Chromebooks. Dropbox appears as a new drive in the left column of Files app just like Drive.
This software provides you an ability to mount your Dropbox to Chrome OS (unofficial software).
* Works on only ChromeOS.
* Will unmount automatically when the access token is expired to access Dropbox Core API.