Code review comment for lp://qastaging/~fourdollars/unity-greeter/add-hidpi-support

BTW, by the internal design of GTK+3/GDK, unity-settings-daemon/gnome-settings-daemon should be started before any GTK+3/GDK based application.
Because the xsettings plugin will bring up a property called '_XSETTINGS_SETTINGS', and every GTK+3/GDK based application will look for this property to set the proper scale factor when it starts.
This scale factor will be changed with "gsettings get org.gnome.desktop.interface scaling-factor".
The current design of unity-greeter will execute Gtk.init() or Gdk.init() before unity-settings-daemon starts, so the scale factor is already set as 1 by default because it can not find the X property '_XSETTINGS_SETTINGS'.
If we can execute unity-settings-daemon before Gtk.init()/Gdk.init() and make sure the X property '_XSETTINGS_SETTINGS' is already there, we may not need this patch.