Bug 9818 Java Browsing: Editor with non-java resource flushes views
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/browsing/JavaBrowsingPart.java
* @return	<true> if the given element is a valid element
	 */
	protected boolean isValidElement(Object element) {
		if (element == null)
			return false;
		element= getSuitableJavaElement(element);
		if (element == null)
			return false;
		Object input= getViewer().getInput();
		if (input == null)
			return false;
		if (input instanceof Collection)
			return ((Collection)input).contains(element);
		else
			return input.equals(element);
	}
	private boolean isInputResetBy(Object newInput, Object input, IWorkbenchPart part) {
		if (newInput == null)
			return part == fInputSource;
		if (input instanceof IJavaElement && newInput instanceof IJavaElement)
			return getTypeComparator().compare(newInput, input)  >= 0;
		else
			return false;
	}
	boolean isAncestorOf(Object ancestor, Object element) {
		if (element instanceof IJavaElement && ancestor instanceof IJavaElement)
			return element.equals(ancestor) || isAncestorOf(ancestor, ((IJavaElement)element).getParent());
		return false;
	}
	public void selectionChanged(IWorkbenchPart part, ISelection selection) {