[IMP]Applied reviewed changes.

web_x2many_delete_all/static/src/css/web_x2many_delete_all.css

@@ -1,7 +0,0 @@
-/* Copyright 2016 Onestein
- * License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). */
-
-table.o_list_view th.o_list_record_delete,
-table.o_list_view th.o_list_record_delete span {
-    cursor: pointer;
-}

web_x2many_delete_all/static/src/js/web_x2many_delete_all.js

@@ -21,7 +21,9 @@ odoo.define('web_x2many_delete_all.Mixin', function (require) {
         _renderDeleteAll: function (tag) {
             var $icon = $('<button>', {class: 'fa fa-trash-o o_list_record_delete_all_btn', name: 'delete all',
                 'aria-label': _t('Delete All')});
-            return $('<th>', {class: 'o_list_record_delete_all'}).append($icon);
+            return $('<' + tag + ' width="1">')
+                    .addClass('o_list_record_delete_all')
+                    .append($icon);
         },
         _onTrashAllIconClick: function (event) {
             event.stopPropagation();