A Boolean value representing whether the field is set to Auto height in the Editor.
The extension may choose to respond to this by providing the height of the field whenever requested by Agentry depending on what it wants to display. See model:wantsViewHeightForWidth: (SMPOpenUIFieldAdapter-p) in the SMPOpenUIFieldAdapter protocol.
The extension may also choose to notify Agentry that it wants a new height for an autosizing field via the method requestLayoutHeigh: in this protocol.