NOTE: This feature only works on documents stored in Google Drive or Dropbox.
While making annotations or editing a document, you can easily identify a document's syncing and saving status here:
To restore a document back to its original version, you can click this hyperlink.
After clicking the link, you will be taken to a preview of the current version of the document and other saved versions.
Click the Original version, then click Restore.
Click, Restore to complete the action.
WARNING: This action is irreversible, when a document is restored, ALL annotations/edits will be removed.