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.device.extension/src/org/eclipse/birt/chart/device/swing/SwingRendererImpl.java
final Trigger[] tga = iev.getTriggers( );
		if ( tga == null )
		{
			return;
		}
		
		ShapedAction sa = getShapedAction( iev );
		if ( sa != null )
		{
			
			registerTriggers( tga, sa );
		}
	}
	protected ShapedAction getShapedAction( InteractionEvent iev )
	{
		Shape clipping = _g2d.getClip( );
		final PrimitiveRenderEvent pre = iev.getHotSpot( );
		if ( pre instanceof PolygonRenderEvent )
		{
			final Location[] loa = ( (PolygonRenderEvent) pre ).getPoints( );
			return new ShapedAction( iev.getStructureSource( ), loa, clipping );
		}
		else if ( pre instanceof RectangleRenderEvent )
		{
			final Bounds bo = ( (RectangleRenderEvent) pre ).getBounds( );
			final Location[] loa = new Location[4];
			loa[0] = LocationImpl.create( bo.getLeft( ), bo.getTop( ) );
			loa[1] = LocationImpl.create( bo.getLeft( ), bo.getTop( )
					+ bo.getHeight( ) );
			loa[2] = LocationImpl.create( bo.getLeft( ) + bo.getWidth( ),