Bug 275910 [Widgets] PaintListener on Tree not invoked when item count is 0
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
* (non-Javadoc)
			 * 
			 * @seeorg.eclipse.ui.IPartListener2#partClosed(org.eclipse.ui.
			 * IWorkbenchPartReference)
			 */
			public void partClosed(IWorkbenchPartReference partRef) {
				
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see
			 * org.eclipse.ui.IPartListener2#partDeactivated(org.eclipse.ui.
			 * IWorkbenchPartReference)
			 */
			public void partDeactivated(IWorkbenchPartReference partRef) {
				
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @seeorg.eclipse.ui.IPartListener2#partHidden(org.eclipse.ui.
			 * IWorkbenchPartReference)
			 */
			public void partHidden(IWorkbenchPartReference partRef) {
				if (partRef.getId().equals(getSite().getId())) {
					Markers markers = getActiveViewerInputClone();
					Integer[] counts = markers.getMarkerCounts();
					setTitleToolTip(getStatusMessage(markers, counts));
				}