Bug 28575 Hierarchy view updates items twice [type hierarchy]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
/**
	 * view part becomes visible
	 */
	protected void visibilityChanged(boolean isVisible) {
		fIsVisible= isVisible;
		if (isVisible && fNeedRefresh) {
			doTypeHierarchyChanged(fHierarchyLifeCycle, null);
		}
		fNeedRefresh= false;
	}
	
	
	/**
	 * Link selection to active editor.
	 */
	protected void editorActivated(IEditorPart editor) {
		if (!PreferenceConstants.getPreferenceStore().getBoolean(PreferenceConstants.LINK_TYPEHIERARCHY_TO_EDITOR)) {
			return;
		}
		if (fInputElement == null) {
			
			return;
		}
		
		IJavaElement elem= (IJavaElement)editor.getEditorInput().getAdapter(IJavaElement.class);
		try {
			TypeHierarchyViewer currentViewer= getCurrentViewer();
			if (elem instanceof IClassFile) {