Bug 26109 [Dialogs] Need a FormData version of the button sizing API
The button sizing API in Dialog assumes the developer wants a GridData. We should promote the FormData version in PathVariablesDialog to Dialog.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
* 
 * @return the OK button or <code>null</code>
 * 
 * @see createButton
 * @since 2.0
 * @deprecated Use <code>getButton(IDialogConstants.OK_ID)</code> instead.
 * 		This method will be removed soon.
 */
protected Button getOKButton() {
	return getButton(IDialogConstants.OK_ID);
}
/**
 * Initializes the computation of horizontal and vertical dialog units
 * based on the size of current font.
 * <p>
 * This method must be called before any of the dialog unit based
 * conversion methods are called.
 * </p>
 *
 * @param control a control from which to obtain the current font
 */
protected void initializeDialogUnits(Control control) {
	
	GC gc = new GC(control);
	gc.setFont(control.getFont());
	fontMetrics = gc.getFontMetrics();
	gc.dispose();
}
/**
 * Notifies that the ok button of this dialog has been pressed.