content will never be None for no data, it will be ""
When the script access cookie or any file while the browser is running, it get a PermissionDenied error and the whole script stop. Handle the exception.
Sometimes accessing the cookie will return an empty byte b''. if the byte is empty, don't decrypt_password() it.
On my Windows 10 with Google Chrome installed, when I create a new user, that user will have the Chrome's browser directory without any file. The script will fail at File not found error. Checking if the Local State directory exists can mitigate this error.