buffet/etc/dbus-1/org.chromium.Buffet.conf

<!DOCTYPE busconfig PUBLIC
 "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
  <policy user="root">
    <allow send_destination="org.chromium.Buffet" />
  </policy>

  <policy user="buffet">
    <allow own="org.chromium.Buffet" />
    <allow send_destination="org.chromium.Buffet" />
  </policy>

  <policy context="default">
    <deny send_destination="org.chromium.Buffet" />
  </policy>
</busconfig>