NS_INIT_ISUPPORTS();
DefaultTooltipTextProvider::DefaultTooltipTextProvider(){    NS_INIT_ISUPPORTS();        // There are certain element types which we don't want to use    // as tool tip text.     mTag_dialog       = getter_AddRefs(NS_NewAtom("dialog"));    mTag_dialogheader = getter_AddRefs(NS_NewAtom("dialogheader"));    mTag_window       = getter_AddRefs(NS_NewAtom("window"));   }