Bug 30751 [Viewers] Closing all projects doesnt clear package browser list [browsing]
In the java browsing perspective, if you close all projects, the packages browser still has a list of all the packages from the last opened project.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* <code>false</code> to only update labels as needed, assuming that labels
 * for existing elements are unchanged.
 * 
 * @since 2.0
 */
public void refresh(final Object element, final boolean updateLabels) {
	preservingSelection(new Runnable() {
		public void run() {
			internalRefresh(element, updateLabels);
		}
	});
}
/**
 * Refreshes the given TableItem with the given element.
 * Calls <code>doUpdateItem(..., false)</code>.
 * <p>
 * This method is internal to the framework; subclassers should not call
 * this method.
 * </p>
 */
protected final void refreshItem(Widget widget, Object element) {
	safeUpdateItem.widget = widget;
	safeUpdateItem.object = element;
	safeUpdateItem.fullMap = false;
	Platform.run(safeUpdateItem);
}
/**
 * Removes the given open listener from this viewer.
 * Has no affect if an identical listener is not registered.
 *