Revert of Import wpt@a99ba661fff2fb129894bdff21d63814d9b3f7e9

third_party/WebKit/LayoutTests/imported/wpt/custom-elements/resources/custom-elements-helpers.js

 function create_window_in_test(t, srcdoc) {
   let p = new Promise((resolve) => {
     let f = document.createElement('iframe');
     f.srcdoc = srcdoc ? srcdoc : '';
     f.onload = (event) => {
       let w = f.contentWindow;
       t.add_cleanup(() => f.parentNode && f.remove());
       resolve(w);
     };
     document.body.appendChild(f);
@@ skipping 61 matching lines @@
 
 function create_disconnected_callback_log(element) {
     return {type: 'disconnected', element: element};
 }
 
 function assert_disconnected_log_entry(log, element) {
     assert_equals(log.type, 'disconnected');
     assert_equals(log.element, element);
 }
 
-function assert_adopted_log_entry(log, element) {
-    assert_equals(log.type, 'adopted');
-    assert_equals(log.element, element);
-}
-
-function create_adopted_callback_log(element) {
-    return {type: 'adopted', element: element};
-}
-
 function create_attribute_changed_callback_log(element, name, oldValue, newValue, namespace) {
     return {
         type: 'attributeChanged',
         element: element,
         name: name,
         namespace: namespace,
         oldValue: oldValue,
         newValue: newValue,
         actualValue: element.getAttributeNS(namespace, name)
     };
@@ skipping 120 matching lines @@
                     xhr.overrideMimeType('text/xml');
                     xhr.onload = function () { resolve(xhr.responseXML); }
                     xhr.onerror = function () { reject('Failed to fetch the document'); }
                     xhr.send();
                 });
             },
             hasBrowsingContext: false,
         }
     ];
 }