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
private void updateHistoryEntries() {
		for (int i= fInputHistory.size() - 1; i >= 0; i--) {
			IJavaElement type= (IJavaElement) fInputHistory.get(i);
			if (!type.exists()) {
				fInputHistory.remove(i);
			}
		}
		fHistoryDropDownAction.setEnabled(!fInputHistory.isEmpty());
	}
	
	/**
	 * Goes to the selected entry, without updating the order of history entries.
	 */	
	public void gotoHistoryEntry(IJavaElement entry) {
		if (fInputHistory.contains(entry)) {
			updateInput(entry);
		}
	}	
	
	/**
	 * Gets all history entries.
	 */
	public IJavaElement[] getHistoryEntries() {
		if (fInputHistory.size() > 0) {
			updateHistoryEntries();
		}
		return (IJavaElement[]) fInputHistory.toArray(new IJavaElement[fInputHistory.size()]);
	}
	
	/**