Create the event_window at the right size using the same logic as in

Create the event_window at the right size using the same logic as in

Fri Mar 12 15:06:44 2004  Owen Taylor  <otaylor@redhat.com>

        * gtk/gtkexpander.c (gtk_expander_realize): Create the
        event_window at the right size using the same logic as
        in size_allocate. (#136994, Niklas Knuttson)