Bug 55604 [implementation] JavaOutlinePage should dispose CustomFiltersActionGroup
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaOutlinePage.java
fOutlineViewer.setContentProvider(new ChildrenProvider());
		fOutlineViewer.setLabelProvider(new DecoratingJavaLabelProvider(lprovider));
		
		Object[] listeners= fSelectionChangedListeners.getListeners();
		for (int i= 0; i < listeners.length; i++) {
			fSelectionChangedListeners.remove(listeners[i]);
			fOutlineViewer.addSelectionChangedListener((ISelectionChangedListener) listeners[i]);
		}
		
		listeners= fPostSelectionChangedListeners.getListeners();
		for (int i= 0; i < listeners.length; i++) {
			fPostSelectionChangedListeners.remove(listeners[i]);
			fOutlineViewer.addPostSelectionChangedListener((ISelectionChangedListener) listeners[i]);
		}
						
		MenuManager manager= new MenuManager(fContextMenuID, fContextMenuID);
		manager.setRemoveAllWhenShown(true);
		manager.addMenuListener(new IMenuListener() {
			public void menuAboutToShow(IMenuManager m) {
				contextMenuAboutToShow(m);
			}
		});
		fMenu= manager.createContextMenu(tree);
		tree.setMenu(fMenu);
		
		IPageSite site= getSite();
		site.registerContextMenu(JavaPlugin.getPluginId() + ".outline", manager, fOutlineViewer); 
		site.setSelectionProvider(fOutlineViewer);
		
		fActionGroups= new CompositeActionGroup(new ActionGroup[] {