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.pdf/src/org/eclipse/birt/chart/device/pdf/PDFRendererImpl.java
{
			throw new ChartException( ChartDeviceSVGPlugin.ID,
					ChartException.RENDERING,
					"SVGRendererImpl.exception.UnableToWriteChartImage", 
					new Object[]{
						oOutputIdentifier
					},
					null );
		}
		
	}
	
    /**
     * Transcode SVG format data from a transcoder input into PNG format data and
     * write it to a transcoder output.
     *
     * @param tin  the TranscoderInput
     * @param tout  the TranscoderOutput
     *
     * @throws TranscoderException
     */
    protected void transcode2PDF(TranscoderInput tcin, TranscoderOutput tcout)
        throws TranscoderException
    {
        
        PDFTranscoder t = new PDFTranscoder();
        
        t.setErrorHandler(new DefaultErrorHandler()
        {
            public void error(TranscoderException te)