DockLayoutPanel resize south to fit children using UIBinder?

[Micah Caldwell]

I am using a DockLayoutPanel to setup a tab bar in the north, a CellList in the west, content in the center and a simple "form" in the bottom (text field and button).  The south area is where I am having problems because I want the height of that area to automatically fit whatever is in there (the input field).  I am able to set it to a fixed size but I would like something that won't break when I change the size of the button or text field that are inside the south area.  Right now they are in a Horizontal Panel, but I can change that if someone has a better idea.