createElement should not transmit exceptions but report them.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 640 matching lines @@
         InvalidCharacterError,
         "The tag name provided ('" + name + "') is not a valid name.");
     return nullptr;
   }
 
   if (isXHTMLDocument() || isHTMLDocument()) {
     // 2. If the context object is an HTML document, let localName be
     // converted to ASCII lowercase.
     AtomicString localName = convertLocalName(name);
     if (CustomElement::shouldCreateCustomElement(localName))
-      return CustomElement::createCustomElementSync(*this, localName,
-                                                    exceptionState);
+      return CustomElement::createCustomElementSync(*this, localName);
     return HTMLElementFactory::createHTMLElement(localName, *this, 0,
                                                  CreatedByCreateElement);
   }
 
   return Element::create(QualifiedName(nullAtom, name, nullAtom), this);
 }
 
 Element* Document::createElement(const AtomicString& localName,
                                  const AtomicString& typeExtension,
                                  ExceptionState& exceptionState) {
   if (!isValidName(localName)) {
     exceptionState.throwDOMException(
         InvalidCharacterError,
         "The tag name provided ('" + localName + "') is not a valid name.");
     return nullptr;
   }
 
   Element* element;
 
   if (CustomElement::shouldCreateCustomElement(convertLocalName(localName))) {
     element = CustomElement::createCustomElementSync(
-        *this, convertLocalName(localName), exceptionState);
+        *this, convertLocalName(localName));
   } else if (V0CustomElement::isValidName(localName) && registrationContext()) {
     element = registrationContext()->createCustomTagElement(
         *this, QualifiedName(nullAtom, convertLocalName(localName),
                              xhtmlNamespaceURI));
   } else {
     element = createElement(localName, exceptionState);
     if (exceptionState.hadException())
       return nullptr;
   }
 
@@ skipping 28 matching lines @@
 
 Element* Document::createElementNS(const AtomicString& namespaceURI,
                                    const AtomicString& qualifiedName,
                                    ExceptionState& exceptionState) {
   QualifiedName qName(
       createQualifiedName(namespaceURI, qualifiedName, exceptionState));
   if (qName == QualifiedName::null())
     return nullptr;
 
   if (CustomElement::shouldCreateCustomElement(qName))
-    return CustomElement::createCustomElementSync(*this, qName, exceptionState);
+    return CustomElement::createCustomElementSync(*this, qName);
   return createElement(qName, CreatedByCreateElement);
 }
 
 Element* Document::createElementNS(const AtomicString& namespaceURI,
                                    const AtomicString& qualifiedName,
                                    const AtomicString& typeExtension,
                                    ExceptionState& exceptionState) {
   QualifiedName qName(
       createQualifiedName(namespaceURI, qualifiedName, exceptionState));
   if (qName == QualifiedName::null())
     return nullptr;
 
   Element* element;
   if (CustomElement::shouldCreateCustomElement(qName))
-    element =
-        CustomElement::createCustomElementSync(*this, qName, exceptionState);
+    element = CustomElement::createCustomElementSync(*this, qName);
   else if (V0CustomElement::isValidName(qName.localName()) &&
            registrationContext())
     element = registrationContext()->createCustomTagElement(*this, qName);
   else
     element = createElement(qName, CreatedByCreateElement);
 
   if (!typeExtension.isEmpty())
     V0CustomElementRegistrationContext::setIsAttributeAndTypeExtension(
         element, typeExtension);
 
@@ skipping 5637 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif