Bug 336225 Trim bars do not get unrendered by the rendering engine when trimmed window is unrendered
The trim bars are "ignored" by the rendering engine as it does not perform an unrendering pass on them when the parent trimmed window is being unrendered.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
.createPerspective();
		perspectiveStack.getChildren().add(perspective2);
		MPlaceholder partPlaceholder2 = AdvancedFactoryImpl.eINSTANCE
				.createPlaceholder();
		partPlaceholder2.setRef(part);
		perspective2.getChildren().add(partPlaceholder2);
		perspective2.setSelectedElement(partPlaceholder2);
		application.setContext(appContext);
		appContext.set(MApplication.class.getName(), application);
		wb = new E4Workbench(application, appContext);
		wb.createAndRunUI(window);
		IEclipseContext perspectiveContext1 = perspective1.getContext();
		IEclipseContext partContext = part.getContext();
		assertEquals(perspectiveContext1, partContext.getParent());
		assertEquals(partContext, perspectiveContext1.getActiveChild());
		EPartService partService = window.getContext().get(EPartService.class);
		partService.switchPerspective(perspective2);
		IEclipseContext perspectiveContext2 = perspective2.getContext();
		assertEquals(partContext, perspectiveContext1.getActiveChild());
		assertEquals(perspectiveContext2, partContext.getParent());
		assertEquals(partContext, perspectiveContext2.getActiveChild());
		partService.hidePart(part);
		assertEquals(perspectiveContext1, partContext.getParent());
		assertEquals(partContext, perspectiveContext1.getActiveChild());
		assertNull(
				"perspective2 doesn't have any parts, it should not have an active child context",
				perspectiveContext2.getActiveChild());
	}
	public void testBug334644_01() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE