Bug 194549 Memory leak in chart device renderers
After memory analysis for Chart code, it indicates java.awt.Font objects are not garbage collected. Investigating the renderer code, Graphics2D objects in IDisplayServer and IDeviceRenderer are not disposed after chart rendering finished. Need to invoke IDeviceRenderer.dispose() after ChartReportItemPresentationImpl being finished, and dispose all required resources in that method, including IDisplayServer and anything else.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/device/IDisplayServer.java
{
	/**
	 * Lists out all resources that were previously logged explicitly by the
	 * <code>logCreation(Object)</code> method or those internally created by
	 * each of the resource creation methods. Once this method is invoked, all
	 * entries written into the log should be flushed.
	 */
	void debug( );
	/**
	 * Log creation of a resource for which leaks are to be tracked
	 * 
	 * @param o
	 *            A device-specific object being created
	 */
	void logCreation( Object o );
	/**
	 * Attempts to create a new font resource associated with a specific device
	 * for use in rendering or computations
	 * 
	 * @param fd
	 *            An font description for which a device specific resource is