Custom Elements: layout tests for custom built-in elements definition

third_party/WebKit/LayoutTests/custom-elements/spec/define-element-expected.txt

+This is a testharness.js-based test.
+PASS A "constructor" that is not a constructor 
+PASS Invalid names 
+PASS Duplicate name 
+PASS Duplicate name defined recursively 
+PASS Reused constructor 
+PASS HTMLElement constructor looks up definitions in the current global-reused constructor 
+FAIL Invalid extends value assert_throws: extends value must not be valid customized element name function "() => {
+    try {
+      func.call(this);
+    } catch(e) {
+      exception = e;
+      throw e;
+    }
+  }" did not throw
+FAIL Invalid extends value assert_throws: extends value cannot be HTMLUnknownElement function "() => {
+    try {
+      func.call(this);
+    } catch(e) {
+      exception = e;
+      throw e;
+    }
+  }" did not throw
+FAIL Localname should be extends value not defined-name promise_test: Unhandled rejection with value: object "TypeError: Illegal constructor"
+PASS HTMLElement constructor looks up definitions in the current global 
+PASS Reused constructor recursively 
+PASS Define while element definition is running 
+PASS Define while element definition is running in a separate registry 
+PASS Element definition flag resets before upgrades 
+PASS Order of checks 
+PASS Upgrade: existing elements 
+PASS Upgrade: sets prototype of existing elements 
+PASS Upgrade: shadow tree 
+PASS If an exception is thrown, rethrow that exception and terminate the algorithm 
+PASS Rethrow any exceptions thrown while getting prototype 
+PASS Retrieved prototype is a non-object 
+PASS Rethrow any exceptions thrown while retrieving attributeChangedCallback 
+PASS Rethrow any exceptions thrown while retrieving disconnectedCallback 
+PASS Rethrow any exceptions thrown while retrieving connectedCallback 
+PASS If retrieved callback attributeChangedCallback is not undefined and not callable, throw TypeError 
+PASS If retrieved callback disconnectedCallback is not undefined and not callable, throw TypeError 
+PASS If retrieved callback connectedCallback is not undefined and not callable, throw TypeError 
+PASS Rethrow any exceptions thrown while getting observedAttributes 
+PASS exception thrown while converting observedAttributes to sequence<DOMString> should be rethrown 
+PASS Get(constructor, observedAttributes) should not execute if attributeChangedCallback is undefined 
+PASS Invalid constructor 
+PASS Invalid constructor 
+PASS Invalid constructor 
+Harness: the test ran to completion.
+