Bug 326175 WBWRenderer arbitrarily modifies the window's parent's active context chain
The window's parent's context arbitrarily changes its active child to the window being rendered in createWidget(*).
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
.createPlaceholder();
		partPlaceholderA1.setRef(part);
		part.setCurSharedRef(partPlaceholderA1);
		perspective1.getChildren().add(partPlaceholderA1);
		perspective1.setSelectedElement(partPlaceholderA1);
		MPerspective perspective2 = AdvancedFactoryImpl.eINSTANCE
				.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());