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
perspectiveB.getChildren().add(partPlaceholderB2);
		initialize(applicationContext, application);
		getEngine().createGui(window);
		EPartService partService = window.getContext().get(EPartService.class);
		partService.activate(partB);
		partService.switchPerspective(perspectiveB);
		assertEquals(
				"partB is in both perspectives, active part should have been preserved",
				partB, partService.getActivePart());
		partService.hidePart(partB);
		assertEquals("Hiding partB should have caused partA to be activated",
				partA, partService.getActivePart());
		partService.switchPerspective(perspectiveA);
		assertEquals(
				"partA is in both perspectives, active part should have been preserved",
				partA, partService.getActivePart());
		partService.activate(partB);
		assertEquals("partB should have been activated by activate(MPart)",
				partB, partService.getActivePart());
		partService.switchPerspective(perspectiveB);
		assertEquals(
				"partA should be the only part that's being shown in perspectiveB, thus, it should be the active part",
				partA, partService.getActivePart());
	}
	/**
	 * Test to ensure that switching perspectives doesn't cause a hidden shared
	 * part to be displayed again.
	 */
	public void testHidePart_ActivationHistory16B() {
		MApplication application = ApplicationFactoryImpl.eINSTANCE