Bug 328339 Part activation history seems to ignore detached windows
1. Detach a view. 2. Drag another view into said detached window. 3. Activate the two views alternatively. 4. Close one of them. 5. A part in the workbench window is activated instead of the other view in the detached window.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
areaPlaceholder.setRef(area);
		area.setCurSharedRef(areaPlaceholder);
		perspective.getChildren().add(areaPlaceholder);
		MPartStack stackB = BasicFactoryImpl.eINSTANCE.createPartStack();
		area.getChildren().add(stackB);
		area.setSelectedElement(stackB);
		MPartStack stackC = BasicFactoryImpl.eINSTANCE.createPartStack();
		area.getChildren().add(stackC);
		MPart partB = BasicFactoryImpl.eINSTANCE.createPart();
		stackB.getChildren().add(partB);
		stackB.setSelectedElement(partB);
		MPart partC = BasicFactoryImpl.eINSTANCE.createPart();
		stackC.getChildren().add(partC);
		stackC.setSelectedElement(partC);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partA);
		partService.activate(partB);
		partService.activate(partA);
		partService.activate(partB);
		partService.hidePart(partB);
		assertEquals(partC, partService.getActivePart());
	}
	public void testHidePart_ActivationHistory10() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window);
		application.setSelectedElement(window);