Bug 326177 EPartService's getActivePart() does not appear to work properly for an application with multiple windows
Based on the code in PartServiceCreationFunction, the EPartService implementation being returned when an application's context is queried seems to be a window-level EPartService implementation.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
testSaveAll_NoHandlers(false, new boolean[] { false, false },
				new boolean[] { true, false });
	}
	public void testSaveAll_NoHandlers_F_FF_FT() {
		testSaveAll_NoHandlers(false, new boolean[] { false, false },
				new boolean[] { false, true });
	}
	public void testSaveAll_NoHandlers_F_FF_FF() {
		testSaveAll_NoHandlers(false, new boolean[] { false, false },
				new boolean[] { false, false });
	}
	public void testSwitchWindows() {
		
		MApplication application = ApplicationFactoryImpl.eINSTANCE
				.createApplication();
		MWindow window1 = BasicFactoryImpl.eINSTANCE.createWindow();
		MWindow window2 = BasicFactoryImpl.eINSTANCE.createWindow();
		application.getChildren().add(window1);
		application.getChildren().add(window2);
		application.setSelectedElement(window1);
		
		MPart part = BasicFactoryImpl.eINSTANCE.createPart();
		window1.getChildren().add(part);
		window1.setSelectedElement(part);
		
		initialize(applicationContext, application);
		
		getEngine().createGui(window1);
		getEngine().createGui(window2);
		EPartService windowService1 = (EPartService) window1.getContext().get(