Import wpt@26c8d4e87448d1c4e5ebf2ddb4917c0633c201db

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 47 matching lines @@
         connectedCallback() { log.push({type: 'connected', element: this}); }
         disconnectedCallback() { log.push({type: 'disconnected', element: this}); }
         adoptedCallback(oldDocument, newDocument) { log.push({type: 'adopted', element: this, oldDocument: oldDocument, newDocument: newDocument}); }
     }
     CustomElement.observedAttributes = observedAttributes;
 
     customElements.define(name, CustomElement);
 
     return {
         name: name,
+        class: CustomElement,
         takeLog: function () {
             let currentLog = log; log = [];
             currentLog.types = () => currentLog.map((entry) => entry.type);
             currentLog.last = () => currentLog[currentLog.length - 1];
             return currentLog;
         }
     };
 }
 define_new_custom_element._element_number = 1;
 
@@ skipping 75 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,
         }
     ];
 }