Bug 208373 Auto resize Chart to have a single axis without blank
When Chart is within Cross tab, chart axis image should have a single axis only, but there may be much blank in other area. Chart engine should auto resize the image to have the axis with fit size. Meanwhile, report engine should not set size for chart image.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/factory/Generator.java
*            The Chart model
	 * @return All row expressions in a list of String instances.
	 * @throws ChartException
	 * 
	 * @since 2.0
	 */
	public List getRowExpressions( Chart cm ) throws ChartException
	{
		return getRowExpressions( cm, null );
	}
	/**
	 * This retrieves all the row expressions stored in the chart model. This is
	 * useful to prepare a specific query for the chart. If the given
	 * IActionEvaluator is not null, then it will also search available
	 * expressions within the action.
	 * 
	 * @param cm
	 *            The Chart model
	 * @param iae
	 *            An IActionEvaluator instance
	 * @return All row expressions in a list of String instances.
	 * @throws ChartException
	 * 
	 * @since 2.0
	 */
	public List getRowExpressions( Chart cm, IActionEvaluator iae )
			throws ChartException
	{
		if ( cm instanceof ChartWithAxes )
		{