Add tests of state changes for :defined() selector

third_party/WebKit/LayoutTests/custom-elements/spec/selectors/pseudo-class-defined.html

Index: third_party/WebKit/LayoutTests/custom-elements/spec/selectors/pseudo-class-defined.html
diff --git a/third_party/WebKit/LayoutTests/custom-elements/spec/selectors/pseudo-class-defined.html b/third_party/WebKit/LayoutTests/custom-elements/spec/selectors/pseudo-class-defined.html
index a248f121b1ae9c9f8e2dc78ff829c16b4af62cdc..6f1e191bd07346b6925c9c4b5fb24eadfc951b07 100644
--- a/third_party/WebKit/LayoutTests/custom-elements/spec/selectors/pseudo-class-defined.html
+++ b/third_party/WebKit/LayoutTests/custom-elements/spec/selectors/pseudo-class-defined.html
@@ -39,19 +39,30 @@ iframe.onload = () => {
 
 function test_defined_for_createElement(defined, doc, tagName, description = '') {

[dominicc (has gone to gerrit), 2016/06/07 12:01:06]

Nit: Consider tagName -> tag_name if you're going to write svg_element?

[kojii, 2016/06/07 18:59:31]

Done. testharness.js forcing us to mix styles always confuses me, I wish it was
consistent with DOM...

   // Test document.createElement().
-  let element = doc.createElement(tagName);
+  const element = doc.createElement(tagName);

[dominicc (has gone to gerrit), 2016/06/07 12:01:05]

Why const and not let?

[kojii, 2016/06/07 18:59:31]

Changed back to let. Read somewhere that I should use const if I were not
re-assigning to the variable, and the change makes it so, but I don't have
opinions.

   doc.body.appendChild(element);
   test_defined(defined, element, `${description}createElement("${tagName}")`);
 
   // Test document.createElementNS().
-  element = doc.createElementNS('http://www.w3.org/1999/xhtml', tagName);
-  doc.body.appendChild(element);
-  test_defined(defined, element, `${description}createElementNS("http://www.w3.org/1999/xhtml", "${tagName}")`);
+  const html_element = doc.createElementNS('http://www.w3.org/1999/xhtml', tagName);
+  doc.body.appendChild(html_element);
+  test_defined(defined, html_element, `${description}createElementNS("http://www.w3.org/1999/xhtml", "${tagName}")`);
 
   // If the element namespace is not HTML, it should be "uncustomized"; i.e., "defined".
-  element = doc.createElementNS('http://www.w3.org/2000/svg', tagName);
-  doc.body.appendChild(element);
-  test_defined(true, element, `${description}createElementNS("http://www.w3.org/2000/svg", "${tagName}")`);
+  const svg_element = doc.createElementNS('http://www.w3.org/2000/svg', tagName);
+  doc.body.appendChild(svg_element);
+  test_defined(true, svg_element, `${description}createElementNS("http://www.w3.org/2000/svg", "${tagName}")`);
+
+  // Test ":defined" changes when the custom element was defined.
+  if (!defined) {
+    const w = doc.defaultView;
+    w.customElements.define(tagName, class extends w.HTMLElement {
+      constructor() { super(); }
+    });

[rune, 2016/06/07 09:39:08]

Would it make sense to test the two other cases in example 2 in
https://dom.spec.whatwg.org/#concept-element-defined as well?

The throwing constructor, and the <p is=""> cases?

[kojii, 2016/06/07 10:48:54]

is="" is not supported yet, it requires quite amount of work, we're planning to
work on it a little later.

Throwing constructor is interesting, I wasn't aware it's in the example. IIUC in
the old spec it should be "undefined" but with
https://github.com/whatwg/html/issues/1297 resolved, I think it should be
"defined" now.

Filed https://github.com/whatwg/html/issues/1396 for clarification.

We'll add that when the spec was clarified. We just got an intern to work on
upstreaming tests to web-platform-tests, this should be a good one for her to
work on.

[rune, 2016/06/07 10:56:00]

Acknowledged.

+
+    test_defined(true, element, `Upgraded ${description}createElement("${tagName}")`);
+    test_defined(true, html_element, `Upgraded ${description}createElementNS("http://www.w3.org/1999/xhtml", "${tagName}")`);
+  }
 }
 
 function test_defined(expected, element, description) {