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
for (int i = 0; i < elements.length; ++i)
		update(elements[i], properties);
}
/**
 * Updates the given element's presentation when one or more of its properties changes.
 * Only the given element is updated.
 * <p>
 * This does not handle structural changes (e.g. addition or removal of elements),
 * and does not update any other related elements (e.g. child elements).
 * To handle structural changes, use the <code>refresh</code> methods instead.
 * </p>
 * <p>
 * This should be called when an element has changed in the model, in order to have the viewer
 * accurately reflect the model.  This method only affects the viewer, not the model.
 * </p>
 * <p>
 * Specifying which properties are affected may allow the viewer to optimize the update.
 * For example, if the label provider is not affected by changes to any of these properties,
 * an update may not actually be required. Specifing <code>properties</code> as 
 * <code>null</code> forces a full update of the element.
 * </p>
 * <p>
 * If the viewer has a sorter which is affected by a change to one of the properties,
 * the element's position is updated to maintain the sort order.
 * </p>
 * <p>
 * If the viewer has a filter which is affected by a change to one of the properties,
 * the element may appear or disappear if the change affects whether or not the element
 * is filtered out.
 * </p>