Bug 36518 call hierarchy: 'refresh' should available only in dropdown menu
toolbar button is not conventional and not accessible we should remove it from there and put in the dropdown menu (context menu is ok, i guess)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyFiltersActionGroup.java
class ShowFilterDialogAction extends Action {
        ShowFilterDialogAction() {
            setText(CallHierarchyMessages.getString("ShowFilterDialogAction.text")); 
            setImageDescriptor(JavaPluginImages.DESC_CLCL_FILTER);
        }
        
        public void run() {
            openDialog();
        }
    }
    private IViewPart fPart;
    private StructuredViewer fViewer;
    /**
     * Creates a new <code>CustomFiltersActionGroup</code>.
     * 
     * @param part      the view part that owns this action group
     * @param viewer    the viewer to be filtered
     */
    public CallHierarchyFiltersActionGroup(IViewPart part, StructuredViewer viewer) {
        Assert.isNotNull(part);
        Assert.isNotNull(viewer);
        fPart= part;
        fViewer= viewer;