Bug 287103 [CommonNavigator] contentServiceLabelProvider doesn't properly implement overrides
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentServiceContentProvider.java
* The results of this method will be displayed in the root of the
	 * TreeViewer.
	 * </p>
	 * {@inheritDoc}
	 * 
	 * @param anInputElement
	 *            The relevant element that a client would like children for -
	 *            the input element of the TreeViewer
	 * @return A non-null array of objects that are logical children of
	 *         anInputElement
	 * @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(java.lang.Object)
	 */
	public synchronized Object[] getElements(Object anInputElement) {
		contentService.resetContributionMemory();
		Set rootContentExtensions = contentService
				.findRootContentExtensions(anInputElement);
		if (rootContentExtensions.size() == 0) {
			return NO_CHILDREN;
		}
		ContributorTrackingSet finalElementsSet = new ContributorTrackingSet(contentService);
		ContributorTrackingSet localSet = new ContributorTrackingSet(contentService);		
		Object[] contributedChildren = null;
		NavigatorContentExtension foundExtension;
		NavigatorContentExtension[] overridingExtensions;
		for (Iterator itr = rootContentExtensions.iterator(); itr.hasNext();) {
			foundExtension = (NavigatorContentExtension) itr.next();
			try {
				if (!isOverridingExtensionInSet(foundExtension.getDescriptor(),
						rootContentExtensions)) {
					contributedChildren = foundExtension.internalGetContentProvider()