Bug 37886 Show type hierarchy cancel ends up with empty dialog
1) open type hierarchy on object 2) cancel ->the search is cancelled but an empty dialog is showing up.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/HierarchyInformationControl.java
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.jdt.core.IClassFile;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IImportDeclaration;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IMember;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.ITypeHierarchy;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.Signature;
import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.text.AbstractInformationControl;
import org.eclipse.jdt.internal.ui.typehierarchy.TraditionalHierarchyViewer.TraditionalHierarchyContentProvider;
import org.eclipse.jdt.internal.ui.viewsupport.DecoratingJavaLabelProvider;
import org.eclipse.jdt.internal.ui.viewsupport.JavaElementLabels;
/**
 *
 */
public class HierarchyInformationControl extends AbstractInformationControl {
	
	private class HierarchyInformationControlLabelProvider extends HierarchyLabelProvider {
		public HierarchyInformationControlLabelProvider(TypeHierarchyLifeCycle lifeCycle) {
			super(lifeCycle);
		}