custom-elements: document.createElementNS() should set prefixes to custom elements.

We had a bug that createElementNS() ignored prefixes.
New behavior matches to the specification and Firefox.

* Document-createElementNS.html:
  Fix a copypasta error.

* ScriptCustomElementDefinition::CreateElementSync:
  Implement Step 6.1.10.

* Document::createElementNS:
  Fix an argument of definition lookup.

* CustomElement::CreateUndefinedElement:
  Use Document::CreateRawElement(), which sets prefixes correctly,
  instead of HTMLElementFactory::createHTMLElement().

* ustomElementDefinition::CreateElementAsync:
  Use Document::CreateRawElement(), which sets prefixes correctly,
  instead of HTMLElementFactory::createRawHTMLElement().

Bug: 806639
Change-Id: I74b431d4475d7cf84f65ab0ff1b24773cbc64079
Reviewed-on: https://chromium-review.googlesource.com/892802Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532821}

third_party/WebKit/LayoutTests/external/wpt/custom-elements/Document-createElementNS-expected.txt

-This is a testharness.js-based test.
-FAIL autonomous: document.createElementNS should create custom elements with prefixes. assert_equals: expected (string) "p" but got (object) null
-PASS autonomous: document.createElementNS should check namespaces.
-FAIL builtin: document.createElementNS should create custom elements with prefixes. Failed to execute 'createElementNS' on 'Document': Custom element definition not found.
-PASS builtin: document.createElementNS should check namespaces.
-Harness: the test ran to completion.
-

third_party/WebKit/LayoutTests/external/wpt/custom-elements/Document-createElementNS.html

@@ -28,7 +28,7 @@ test(() => {
 
   customElements.define('my-builtin', MyBuiltinElement, { extends: 'address' });
   let element = document.createElementNS('http://www.w3.org/1999/xhtml', 'p:address', { is: 'my-builtin'});
-  assert_true(element instanceof MyElement);
+  assert_true(element instanceof MyBuiltinElement);
   assert_equals(element.prefix, 'p');
 }, 'builtin: document.createElementNS should create custom elements with prefixes.');
 

third_party/WebKit/Source/bindings/core/v8/ScriptCustomElementDefinition.cpp

@@ -188,6 +188,9 @@ HTMLElement* ScriptCustomElementDefinition::CreateElementSync(
     return HandleCreateElementSyncException(document, tag_name, isolate,
                                             exception_state);
   }
+  // 6.1.10. Set result’s namespace prefix to prefix.
+  if (element->prefix() != tag_name.Prefix())
+    element->SetTagNameForCreateElementNS(tag_name);
   DCHECK_EQ(element->GetCustomElementState(), CustomElementState::kCustom);
   return ToHTMLElement(element);
 }

third_party/WebKit/Source/core/dom/Document.cpp

@@ -1080,7 +1080,7 @@ Element* Document::createElementNS(const AtomicString& namespace_uri,
   // 2.
   const AtomicString& is =
       AtomicString(GetTypeExtension(this, string_or_options, exception_state));
-  const AtomicString& name = should_create_builtin ? is : qualified_name;
+  const AtomicString& name = should_create_builtin ? is : q_name.LocalName();
 
   if (!IsValidElementName(this, qualified_name)) {
     exception_state.ThrowDOMException(
@@ -1093,9 +1093,7 @@ Element* Document::createElementNS(const AtomicString& namespace_uri,
   CustomElementDefinition* definition = nullptr;
   if (is_v1 && namespace_uri == HTMLNames::xhtmlNamespaceURI) {
     const CustomElementDescriptor desc =
-        RuntimeEnabledFeatures::CustomElementsBuiltinEnabled()
-            ? CustomElementDescriptor(name, qualified_name)
-            : CustomElementDescriptor(qualified_name, qualified_name);
+        CustomElementDescriptor(name, q_name.LocalName());
     if (CustomElementRegistry* registry = CustomElement::Registry(*this))
       definition = registry->DefinitionFor(desc);
 

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

@@ -170,8 +170,8 @@ HTMLElement* CustomElement::CreateUndefinedElement(
     SECURITY_DCHECK(v0element->IsHTMLElement());
     element = ToHTMLElement(v0element);
   } else if (should_create_builtin) {
-    element = HTMLElementFactory::createHTMLElement(
-        tag_name.LocalName(), document, kCreatedByCreateElement);
+    element = ToHTMLElement(
+        document.CreateRawElement(tag_name, kCreatedByCreateElement));
   } else {
     element = HTMLElement::Create(tag_name, document);
   }

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

@@ -6,6 +6,7 @@
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/Attr.h"
+#include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/html/HTMLElement.h"
 #include "core/html/custom/CustomElement.h"
@@ -121,14 +122,13 @@ HTMLElement* CustomElementDefinition::CreateElementAsync(
     // prefix set to prefix, local name set to localName, custom element
     // state set to "undefined", custom element definition set to null,
     // is value set to is, and node document set to document.
-    auto* result = HTMLElementFactory::CreateRawHTMLElement(
-        tag_name.LocalName(), document, flags);
+    auto* result = document.CreateRawElement(tag_name, flags);
     result->SetCustomElementState(CustomElementState::kUndefined);
 
     // 5.4. Otherwise, enqueue a custom element upgrade reaction given
     // result and definition.
     EnqueueUpgradeReaction(result);
-    return result;
+    return ToHTMLElement(result);
   }
 
   // 6. If definition is non-null, then: