Bug 307747 EPartService doesn't render new parts
1. Have a part in a stack, it is the selected part. 2. Show another part in that stack using PartState.CREATE or PartState.VISIBLE. 3. The part should've been rendered. It is not.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
partStack.setSelectedElement(part);
		getEngine().createGui(window);
		EPartService partService = (EPartService) part.getContext().get(
				EPartService.class.getName());
		assertTrue(partService.isPartVisible(part));
	}
	public void testIsPartVisible_ViewNotVisible() {
		MApplication application = createApplication("partId", "partId2");
		MWindow window = application.getChildren().get(0);
		MPartStack partStack = (MPartStack) window.getChildren().get(0);
		partStack.setSelectedElement(partStack.getChildren().get(0));
		getEngine().createGui(window);
		MPart part = partStack.getChildren().get(1);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		assertFalse(partService.isPartVisible(part));
	}
	public void testIsPartVisible_ViewNotVisible_myService() {
		MApplication application = createApplication("partId", "partId2");
		MWindow window = application.getChildren().get(0);
		MPartStack partStack = (MPartStack) window.getChildren().get(0);
		partStack.setSelectedElement(partStack.getChildren().get(0));
		getEngine().createGui(window);
		MPart part1 = partStack.getChildren().get(0);
		MPart part2 = partStack.getChildren().get(1);
		EPartService partService1 = (EPartService) part1.getContext().get(
				EPartService.class.getName());
		assertTrue(partService1.isPartVisible(part1));
		assertFalse(partService1.isPartVisible(part2));
		partService1.activate(part2);