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/SwingDisplayServer.java
* (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.chart.device.DisplayAdapter#setDpiResolution(int)
	 */
	public final void setDpiResolution( int dpi )
	{
		iDpiResolution = dpi;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.devices.IDisplayServer#loadImage(java.lang.String)
	 */
	public Object loadImage( URL url ) throws ChartException
	{
		return _simc.loadImage( url );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.devices.IDisplayServer#getSize(java.lang.Object)
	 */
	public final Size getSize( Object oImage )
	{
		final Image img = (Image) oImage;
		final ImageObserver io = (ImageObserver) _simc.getObserver( );
		return SizeImpl.create( img.getWidth( io ), img.getHeight( io ) );
	}
	/*
	 * (non-Javadoc)