Bug 137315 [Dialogs] Doubleclickable area to restore dialog size is often very small
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
* that it may be restored.
	 */
	private Point computedSize;
	/**
	 * Number of horizontal dialog units per character, value <code>4</code>.
	 */
	private static final int HORIZONTAL_DIALOG_UNIT_PER_CHAR = 4;
	/**
	 * Number of vertical dialog units per character, value <code>8</code>.
	 */
	private static final int VERTICAL_DIALOG_UNITS_PER_CHAR = 8;
	/**
	 * Returns the number of pixels corresponding to the height of the given
	 * number of characters.
	 * <p>
	 * The required <code>FontMetrics</code> parameter may be created in the
	 * following way: <code>
	 * 	GC gc = new GC(control);
	 *	gc.setFont(control.getFont());
	 *	fontMetrics = gc.getFontMetrics();
	 *	gc.dispose();
	 * </code>
	 * </p>
	 * 
	 * @param fontMetrics
	 *            used in performing the conversion
	 * @param chars
	 *            the number of characters
	 * @return the number of pixels
	 * @since 2.0