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.svg/src/org/eclipse/birt/chart/device/svg/SVGRendererImpl.java
writeDocumentToOutputStream( dom, fos );
				fos.close( );
			}
			catch ( Exception ex )
			{
				throw new ChartException( ChartDeviceSVGPlugin.ID,
						ChartException.RENDERING,
						ex );
			}
		}
		else
		{
			throw new ChartException( ChartDeviceSVGPlugin.ID,
					ChartException.RENDERING,
					"SVGRendererImpl.exception.UnableToWriteChartImage", 
					new Object[]{
						oOutputIdentifier
					},
					null );
		}
		ivRenderer.clear( );
	}
	/**
	 * Writes the XML document to an output stream
	 * 
	 * @param svgDocument
	 * @param outputStream
	 * @throws Exception
	 */
	private void writeDocumentToOutputStream( Document svgDocument,