Bug 46351 Call Hierarchy must not implement IViewSite [call hierarchy]
I20031105 The call hierarchy component implements IViewSite which is not allowed. There seems to be no reason for doing so: the CallHierarchyViewPart should directly set the selection provider to its site.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/SelectionProviderMediator.java
if (viewer != fViewerInFocus) { 
			fViewerInFocus= viewer;
			fireSelectionChanged();
		}
	}
	
	private void fireSelectionChanged() {
		if (fSelectionChangedListeners != null) {
			SelectionChangedEvent event= new SelectionChangedEvent(this, getSelection());
			
			Object[] listeners= fSelectionChangedListeners.getListeners();
			for (int i= 0; i < listeners.length; i++) {
				ISelectionChangedListener listener= (ISelectionChangedListener) listeners[i];
				listener.selectionChanged(event);
			}
		}
	}	
	
	/*
	 * @see ISelectionProvider#addSelectionChangedListener
	 */
	public void addSelectionChangedListener(ISelectionChangedListener listener) {	
		fSelectionChangedListeners.add(listener);
	}
	
	/*
	 * @see ISelectionProvider#removeSelectionChangedListener
	 */
	public void removeSelectionChangedListener(ISelectionChangedListener listener) {
		fSelectionChangedListeners.remove(listener);