Bug 317470 Minimized 'Outline' view has non-white background on restart
1. Minimize the 'Outline' view. 2. Close Eclipse. 3. Start Eclipse. 4. Restore the 'Outline' view. 5. Its background colour is grey instead of white.
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
@Optional
	protected IEventBroker eventBroker;
	@Inject
	EModelService modelService;
	@Inject
	protected Logger logger;
	private Shell limbo;
	@Inject
	public PartRenderingEngine(
			@Named(E4Workbench.RENDERER_FACTORY_URI) @Optional String factoryUrl) {
		if (factoryUrl == null) {
			factoryUrl = defaultFactoryUrl;
		}
		this.factoryUrl = factoryUrl;
	}
	protected void fixZOrder(MUIElement element) {
		MElementContainer<MUIElement> parent = element.getParent();
		if (parent == null || !(element.getWidget() instanceof Control))
			return;
		Control elementCtrl = (Control) element.getWidget();
		Control prevCtrl = null;
		for (MUIElement kid : parent.getChildren()) {
			if (kid == element) {
				if (prevCtrl != null)
					elementCtrl.moveBelow(prevCtrl);
				else
					elementCtrl.moveAbove(null);
				return;
			} else if (kid.getWidget() instanceof Control) {
				prevCtrl = (Control) kid.getWidget();