Bug 319173 [UI] Resizing feedback stops working
While we have seen this on other platforms we have a repeatable test case for the Mac (bogdan, please check if this is the exact scenarion, I'm entering it from memory): Fresh WS, open two other perspectives hit Ctrl-F8 (select perspective) Resize the main window the feedback for the resize doesn't occur until after the mouse button is released.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/TrimBarRenderer.java
* (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.ui.workbench.renderers.PartFactory#createWidget(org.eclipse
	 * .e4.ui.model.application.MPart)
	 */
	@Override
	public Object createWidget(MUIElement element, Object parent) {
		if (!(element instanceof MTrimBar) || !(parent instanceof Composite))
			return null;
		Composite parentComp = (Composite) parent;
		if (!(parentComp.getLayout() instanceof TrimmedPartLayout))
			return null;
		final MTrimBar trimModel = (MTrimBar) element;
		TrimmedPartLayout tpl = (TrimmedPartLayout) parentComp.getLayout();
		Composite result = null;
		switch (trimModel.getSide().getValue()) {
		case SideValue.TOP_VALUE:
			result = tpl.getTrimComposite(parentComp, SWT.TOP);
			break;
		case SideValue.BOTTOM_VALUE:
			result = tpl.getTrimComposite(parentComp, SWT.BOTTOM);
			break;
		case SideValue.LEFT_VALUE:
			result = tpl.getTrimComposite(parentComp, SWT.LEFT);
			break;
		case SideValue.RIGHT_VALUE:
			result = tpl.getTrimComposite(parentComp, SWT.RIGHT);
			break;
		default: