23.0.60; Frame sizing problem with toolbar containing no toolbar buttons

[Tim Van Holder]

CVS emacs of this morning, with GTK toolkit (rebuilt, not bootstrapped).

Buffers with no associated toolbar buttons now show an empty
toolbar (which is probably the actual bug).
But an empty toolbar isn't as high as one with buttons, resulting in
the rest of the frame getting shifted up, leaving a smallish empty
area at the bottom of the frame (below the minibuffer).
So either the toolbar needs to be hidden entirely, or the screen
painting code needs to take this height difference into account.

To reproduce: run report-emacs-bug, enter a subject, and switch
between the message and the *Bug Help* buffer.