Chrome OS PCs have many advantages; however, one of their worst drawbacks is that system recovery requires external media. Now, it appears Google is developing an alternative method: Chromebook restore via Android phone. This new way out of a software failure can only be enacted through a specific keyboard shortcut.
https://www.notebookcheck.net/Chromebooks-may-become-recoverable-using-an-Android-device-soon.436873.0.html