Google Drive Advisory
At this time we strongly discourage the use of Google Drive for synchronising live projects. While this service appears to be stable for the transfer of simple files, complex formats like Scrivener have been known to cause it to fail, reverting, corrupting or even erasing months of work. In the cases we have handled, there has been no way to recover the data if local backups were not available. Please consider using another service for your synchronisation.
There is also a high risk of Google converting Scrivener's internal files to its own proprietary formats, which of course renders the project impossible to read from Scrivener's side. This will result in a difficult recovery procedure of exporting the files back to RTF using Google's web page, and could incur data loss if one uses Scrivener features Google's web site doesn't understand.