createElement should not transmit exceptions but report them.

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

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index e9de0109b839f8b2d872a68740916f080b13b897..03ae8d627184561703f031137d2702d8aeea1e96 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -669,8 +669,7 @@ Element* Document::createElement(const AtomicString& name,
 
   if (isXHTMLDocument() || isHTMLDocument()) {
     if (CustomElement::shouldCreateCustomElement(name))
-      return CustomElement::createCustomElementSync(*this, name,
-                                                    exceptionState);
+      return CustomElement::createCustomElementSync(*this, name);
     return HTMLElementFactory::createHTMLElement(convertLocalName(name), *this,
                                                  0, CreatedByCreateElement);
   }
@@ -691,8 +690,7 @@ Element* Document::createElement(const AtomicString& localName,
   Element* element;
 
   if (CustomElement::shouldCreateCustomElement(localName)) {
-    element = CustomElement::createCustomElementSync(*this, localName,
-                                                     exceptionState);
+    element = CustomElement::createCustomElementSync(*this, localName);
   } else if (V0CustomElement::isValidName(localName) && registrationContext()) {
     element = registrationContext()->createCustomTagElement(
         *this, QualifiedName(nullAtom, convertLocalName(localName),
@@ -741,7 +739,7 @@ Element* Document::createElementNS(const AtomicString& namespaceURI,
     return nullptr;
 
   if (CustomElement::shouldCreateCustomElement(qName))
-    return CustomElement::createCustomElementSync(*this, qName, exceptionState);
+    return CustomElement::createCustomElementSync(*this, qName);
   return createElement(qName, CreatedByCreateElement);
 }
 
@@ -756,8 +754,7 @@ Element* Document::createElementNS(const AtomicString& namespaceURI,
 
   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);