custom-elements: Create appropriate HTMLElement subclasses for custom built-in elements.

Add custom built-in element support to <embed>, <object>, and <form>.

Bug: 805281, 806184, 806185, 806187
Change-Id: I920ea11ed0b5884c69d3c1aee04e18f7fa62e9f2
Reviewed-on: https://chromium-review.googlesource.com/895234Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533234}

third_party/WebKit/LayoutTests/external/wpt/custom-elements/builtin-coverage-expected.txt

 This is a testharness.js-based test.
 Harness Error. harness_status.status = 1 , harness_status.message = Uncaught TypeError: Illegal constructor: localName does not match the HTML element interface
-Found 442 tests; 414 PASS, 28 FAIL, 0 TIMEOUT, 0 NOTRUN.
+Found 442 tests; 423 PASS, 19 FAIL, 0 TIMEOUT, 0 NOTRUN.
 PASS a: Define a customized built-in element
 PASS a: Operator 'new' should instantiate a customized built-in element
 PASS a: document.createElement() should instantiate a customized built-in element
@@ -129,17 +129,9 @@ PASS em: Operator 'new' should instantiate a customized built-in element
 PASS em: document.createElement() should instantiate a customized built-in element
 PASS em: innerHTML should instantiate a customized built-in element
 PASS embed: Define a customized built-in element
-FAIL embed: Operator 'new' should instantiate a customized built-in element Illegal constructor
-FAIL embed: document.createElement() should instantiate a customized built-in element assert_equals: expected function "class MyEmbed extends HTMLEmbedElement {
-  constructor() {
-    super();
-  }
-}" but got function "function HTMLEmbedElement() { [native code] }"
-FAIL embed: innerHTML should instantiate a customized built-in element assert_equals: expected function "class MyEmbed extends HTMLEmbedElement {
-  constructor() {
-    super();
-  }
-}" but got function "function HTMLEmbedElement() { [native code] }"
+PASS embed: Operator 'new' should instantiate a customized built-in element
+PASS embed: document.createElement() should instantiate a customized built-in element
+PASS embed: innerHTML should instantiate a customized built-in element
 PASS fieldset: Define a customized built-in element
 PASS fieldset: Operator 'new' should instantiate a customized built-in element
 PASS fieldset: document.createElement() should instantiate a customized built-in element
@@ -157,17 +149,9 @@ PASS footer: Operator 'new' should instantiate a customized built-in element
 PASS footer: document.createElement() should instantiate a customized built-in element
 PASS footer: innerHTML should instantiate a customized built-in element
 PASS form: Define a customized built-in element
-FAIL form: Operator 'new' should instantiate a customized built-in element Illegal constructor
-FAIL form: document.createElement() should instantiate a customized built-in element assert_equals: expected function "class MyForm extends HTMLFormElement {
-  constructor() {
-    super();
-  }
-}" but got function "function HTMLFormElement() { [native code] }"
-FAIL form: innerHTML should instantiate a customized built-in element assert_equals: expected function "class MyForm extends HTMLFormElement {
-  constructor() {
-    super();
-  }
-}" but got function "function HTMLFormElement() { [native code] }"
+PASS form: Operator 'new' should instantiate a customized built-in element
+PASS form: document.createElement() should instantiate a customized built-in element
+PASS form: innerHTML should instantiate a customized built-in element
 PASS h1: Define a customized built-in element
 PASS h1: Operator 'new' should instantiate a customized built-in element
 PASS h1: document.createElement() should instantiate a customized built-in element
@@ -288,17 +272,9 @@ FAIL noscript: innerHTML should instantiate a customized built-in element assert
   }
 }" but got function "function HTMLElement() { [native code] }"
 PASS object: Define a customized built-in element
-FAIL object: Operator 'new' should instantiate a customized built-in element Illegal constructor
-FAIL object: document.createElement() should instantiate a customized built-in element assert_equals: expected function "class MyObject extends HTMLObjectElement {
-  constructor() {
-    super();
-  }
-}" but got function "function HTMLObjectElement() { [native code] }"
-FAIL object: innerHTML should instantiate a customized built-in element assert_equals: expected function "class MyObject extends HTMLObjectElement {
-  constructor() {
-    super();
-  }
-}" but got function "function HTMLObjectElement() { [native code] }"
+PASS object: Operator 'new' should instantiate a customized built-in element
+PASS object: document.createElement() should instantiate a customized built-in element
+PASS object: innerHTML should instantiate a customized built-in element
 PASS ol: Define a customized built-in element
 PASS ol: Operator 'new' should instantiate a customized built-in element
 PASS ol: document.createElement() should instantiate a customized built-in element

third_party/WebKit/Source/core/html/HTMLEmbedElement.idl

@@ -23,7 +23,8 @@
 // TODO(yukishiino): HTMLEmbedElement should not have [OverrideBuiltins].
 [
     OverrideBuiltins,
-    ActiveScriptWrappable
+    ActiveScriptWrappable,
+    HTMLConstructor
 ] interface HTMLEmbedElement : HTMLElement {
     [CEReactions, Reflect, URL] attribute DOMString src;
     [CEReactions, Reflect] attribute DOMString type;

third_party/WebKit/Source/core/html/HTMLObjectElement.idl

@@ -23,7 +23,8 @@
 // TODO(yukishiino): HTMLObjectElement should not have [OverrideBuiltins].
 [
     OverrideBuiltins,
-    ActiveScriptWrappable
+    ActiveScriptWrappable,
+    HTMLConstructor
 ] interface HTMLObjectElement : HTMLElement {
     [CEReactions, Reflect, URL] attribute DOMString data;
     [CEReactions, Reflect] attribute DOMString type;

third_party/WebKit/Source/core/html/custom/CustomElementDefinition.cpp

@@ -92,13 +92,14 @@ void CustomElementDefinition::CheckConstructorResult(
 
 HTMLElement* CustomElementDefinition::CreateElementForConstructor(
     Document& document) {
-  // TODO(kojii): When HTMLElementFactory has an option not to queue
-  // upgrade, call that instead of HTMLElement. HTMLElement is enough
-  // for now, but type extension will require HTMLElementFactory.
-  HTMLElement* element =
+  HTMLElement* element = HTMLElementFactory::CreateRawHTMLElement(
+      Descriptor().LocalName(), document, kCreatedByCreateElement);
+  if (!element) {
+    element =
         HTMLElement::Create(QualifiedName(g_null_atom, Descriptor().LocalName(),
                                           HTMLNames::xhtmlNamespaceURI),
                             document);
+  }
   // TODO(davaajav): write this as one call to setCustomElementState instead of
   // two
   element->SetCustomElementState(CustomElementState::kUndefined);

third_party/WebKit/Source/core/html/forms/HTMLFormElement.idl

@@ -21,6 +21,7 @@
 // https://html.spec.whatwg.org/#the-form-element
 
 [
+    HTMLConstructor,
     OverrideBuiltins
 ] interface HTMLFormElement : HTMLElement {
     [CEReactions, Reflect=accept_charset] attribute DOMString acceptCharset;