Bug 12449 delete action in type hierarchy is not registered on 'del' key
TypeHierarchyViewPart should call ReorgGroup.createDeleteAction see PackageExplorerViewPart
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
fPartListener= new IPartListener() {
			public void partActivated(IWorkbenchPart part) {
				if (part instanceof IEditorPart)
					editorActivated((IEditorPart) part);
			}
			public void partBroughtToTop(IWorkbenchPart part) {}
			public void partClosed(IWorkbenchPart part) {}
			public void partDeactivated(IWorkbenchPart part) {}
			public void partOpened(IWorkbenchPart part) {}
		};
		
		fSelectionChangedListener= new ISelectionChangedListener() {
			public void selectionChanged(SelectionChangedEvent event) {
				doSelectionChanged(event);
			}
		};
		
	}	
		
	/**
	 * Adds the entry if new. Inserted at the beginning of the history entries list.
	 */		
	private void addHistoryEntry(IJavaElement entry) {
		if (fInputHistory.contains(entry)) {
			fInputHistory.remove(entry);
		}
		fInputHistory.add(0, entry);
		fHistoryDropDownAction.setEnabled(true);
	}