Size of scrolled window

[José Romildo Malaquias <j romildo gmail com>]

One application has a dialog with a tree view widget based on a
list store. The tree view is inside a scrolled window with
PolicyNever and PolicyAutomatic policies for the horizontal and
vertical scrollbars, respectively. See attached image.

How can I automatically get the dialog height large enough to
show as much of the tree view lines as possible, without using
the vertical scrollbar?

José Romildo