Bug 137315 [Dialogs] Doubleclickable area to restore dialog size is often very small
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
* 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(JFaceResources.getDialogFont());
		fontMetrics = gc.getFontMetrics();
		gc.dispose();
	}
	/**
	 * Notifies that the ok button of this dialog has been pressed.
	 * <p>
	 * The <code>Dialog</code> implementation of this framework method sets
	 * this dialog's return code to <code>Window.OK</code> and closes the
	 * dialog. Subclasses may override.
	 * </p>
	 */
	protected void okPressed() {
		setReturnCode(OK);
		close();
	}
	/**
	 * Set the layout data of the button to a GridData with appropriate heights