Implement "create an element" when sync for Custom Element V1

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

 /*
  * Copyright (C) 2006, 2007, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006, 2007 Samuel Weinig <sam@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 36 matching lines @@
     [ImplementedAs=characterSet] readonly attribute DOMString charset; // legacy alias of .characterSet
     [ImplementedAs=characterSet] readonly attribute DOMString inputEncoding; // legacy alias of .characterSet
     readonly attribute DOMString contentType;
 
     readonly attribute DocumentType? doctype;
     readonly attribute Element? documentElement;
     HTMLCollection getElementsByTagName(DOMString localName);
     HTMLCollection getElementsByTagNameNS(DOMString? namespaceURI, DOMString localName);
     HTMLCollection getElementsByClassName(DOMString classNames);
 
-    [NewObject, CustomElementCallbacks, PerWorldBindings, RaisesException] Element createElement(DOMString localName);
-    [NewObject, CustomElementCallbacks, RaisesException] Element createElementNS(DOMString? namespaceURI, DOMString qualifiedName);
+    [NewObject, DoNotTestNewObject, CustomElementCallbacks, PerWorldBindings, RaisesException] Element createElement(DOMString localName);
+    [NewObject, DoNotTestNewObject, CustomElementCallbacks, RaisesException] Element createElementNS(DOMString? namespaceURI, DOMString qualifiedName);

[haraken, 2016/06/13 09:05:35]

Would you help me understand why you need [DoNotTestNewObject]?

[kojii, 2016/06/13 10:28:25]

NewObjet tests if JS wrapper hasn't been created for the native object. With
custom elements, JS constructor already runs for the element with "this" set to
the element, so the test fails.

Consulted with yukishiino, advised to add this attribute in such case. He also
recommended to add DCHECK for such methods, but in this case I couldn't find
good place to add.

     [NewObject] DocumentFragment createDocumentFragment();
     [NewObject] Text createTextNode(DOMString data);
     [NewObject] Comment createComment(DOMString data);
     [NewObject, RaisesException] ProcessingInstruction createProcessingInstruction(DOMString target, DOMString data);
 
     [NewObject, DoNotTestNewObject, CEReactions, CustomElementCallbacks, RaisesException] Node importNode(Node node, optional boolean deep = false);
     [RaisesException, CEReactions, CustomElementCallbacks] Node adoptNode(Node node);
 
     [NewObject, RaisesException, MeasureAs=DocumentCreateAttribute] Attr createAttribute(DOMString localName);
     [NewObject, RaisesException, MeasureAs=DocumentCreateAttributeNS] Attr createAttributeNS(DOMString? namespaceURI, DOMString qualifiedName);
@@ skipping 146 matching lines @@
     [RuntimeEnabled=ExperimentalContentSecurityPolicyFeatures] attribute EventHandler onsecuritypolicyviolation;
     attribute EventHandler onselectionchange;
     attribute EventHandler onselectstart;
     attribute EventHandler onwheel;
 };
 
 Document implements GlobalEventHandlers;
 Document implements ParentNode;
 Document implements NonElementParentNode;
 Document implements DocumentOrShadowRoot;