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
* Builds and computes preferred sizes of various chart components offscreen
	 * using the provided display server.
	 * 
	 * @param ids
	 *            A display server using which the chart may be built.
	 * @param cmDesignTime
	 *            The design time chart model (bound to a dataset).
	 * @param externalContext
	 *            An external context object.
	 * @param bo
	 *            The bounds associated with the chart being built.
	 * @param rtc
	 *            Encapsulates the runtime environment for the build process.
	 * @return An instance of a generated chart state that encapsulates built
	 *         chart information that may be subsequently rendered.
	 * 
	 * @throws ChartException
	 */
	public final GeneratedChartState build( IDisplayServer ids,
			Chart cmDesignTime, Bounds bo, IExternalContext externalContext,
			RunTimeContext rtc ) throws ChartException
	{
		return build( ids, cmDesignTime, bo, externalContext, rtc, null );
	}
	/**
	 * Builds and computes preferred sizes of various chart components offscreen
	 * using the provided display server.
	 * 
	 * @param ids
	 *            A display server using which the chart may be built.