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
bo.getTop( ) + bo.getHeight( ) );
			loa[3] = LocationImpl.create( bo.getLeft( ) + bo.getWidth( ),
					bo.getTop( ) );
			return new ShapedAction( iev.getStructureSource( ), loa, clipping );
		}
		else if ( pre instanceof OvalRenderEvent )
		{
			final Bounds boEllipse = ( (OvalRenderEvent) pre ).getBounds( );
			return new ShapedAction( iev.getStructureSource( ),
					boEllipse,
					clipping );
		}
		else if ( pre instanceof ArcRenderEvent )
		{
			final ArcRenderEvent are = (ArcRenderEvent) pre;
			final Bounds boEllipse = are.getEllipseBounds( );
			double dStart = are.getStartAngle( );
			double dExtent = are.getAngleExtent( );
			int iArcType = toSwingArcType( are.getStyle( ) );
			return new ShapedAction( iev.getStructureSource( ),
					boEllipse,
					dStart,
					dExtent,
					iArcType,
					clipping );
		}
		else if ( pre instanceof AreaRenderEvent )
		{
			final Bounds bo = ( (AreaRenderEvent) pre ).getBounds( );
			final Location[] loa = new Location[4];