Add a scoped context object for synchronous CE creation

third_party/WebKit/Source/core/html/parser/HTMLConstructionSite.cpp

 /*
  * Copyright (C) 2010 Google, Inc. All Rights Reserved.
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 22 matching lines @@
 #include "core/dom/Comment.h"
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/DocumentType.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/IgnoreDestructiveWriteCountIncrementer.h"
 #include "core/dom/ScriptLoader.h"
 #include "core/dom/TemplateContentDocumentFragment.h"
 #include "core/dom/Text.h"
 #include "core/dom/custom/CEReactionsScope.h"
+#include "core/dom/custom/CustomElementCreationScope.h"
 #include "core/dom/custom/CustomElementDefinition.h"
 #include "core/dom/custom/CustomElementDescriptor.h"
 #include "core/dom/custom/CustomElementRegistry.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLHtmlElement.h"
 #include "core/html/HTMLPlugInElement.h"
 #include "core/html/HTMLScriptElement.h"
 #include "core/html/HTMLTemplateElement.h"
@@ skipping 776 matching lines @@
         // level.
         if (1u == m_reentryPermit->scriptNestingLevel())
             Microtask::performCheckpoint(V8PerIsolateData::mainThreadIsolate());
 
         // "6.4 Push a new element queue onto the custom element
         // reactions stack."
         CEReactionsScope reactions;
 
         // 7.
         QualifiedName elementQName(nullAtom, token->name(), HTMLNames::xhtmlNamespaceURI);
-        element = definition->createElementSync(document, elementQName);
+        {
+            CustomElementCreationScope scope(&document);
+            element = definition->createElementSync(document, elementQName);
+        }
 
         // "8. Append each attribute in the given token to element."
         // We don't use setAttributes here because the custom element
         // constructor may have manipulated attributes.
         for (const auto& attribute : token->attributes())
             element->setAttribute(attribute.name(), attribute.value());
 
         // "9. If will execute script is true, then ..." etc. The
         // CEReactionsScope and ScriptNestingLevelIncrementer
         // destructors implement steps 9.1-4.
@@ skipping 129 matching lines @@
     queueTask(task);
 }
 
 DEFINE_TRACE(HTMLConstructionSite::PendingText)
 {
     visitor->trace(parent);
     visitor->trace(nextChild);
 }
 
 } // namespace blink