Bug 271501 [CSS] CSSSWTApplyStylesListener - does it need to shell.pack()
bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/engine/CSSSWTApplyStylesListener.java
private final static String WIDGET_ALREADY_ADDED = "WIDGET_ALREADY_ADDED";
	private CSSEngine engine;
	public CSSSWTApplyStylesListener(Display display, CSSEngine engine) {
		this.engine = engine;
		display.addFilter(SWT.Resize, new ResizeListener());
		display.addFilter(SWT.Show, new ShowListener());
	}
	private final boolean isWidgetAlreadyAdded(Widget widget) {
		if (widget == null)
			return true;
		return widget.getData(WIDGET_ALREADY_ADDED) != null;
	}
	private class ResizeListener implements Listener {