Custom Elements: Check Definition in createElement, Create Customized Built-in Elements Sync

third_party/WebKit/Source/core/dom/custom/CustomElement.h

Index: third_party/WebKit/Source/core/dom/custom/CustomElement.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElement.h b/third_party/WebKit/Source/core/dom/custom/CustomElement.h
index 840e3f22ebd29473d7da5cbdf888755db7d1ce2f..7ae3bca0790325241552832c4462fbab82a31fbb 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElement.h
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElement.h
@@ -65,9 +65,14 @@ class CORE_EXPORT CustomElement {
   static bool shouldCreateCustomElement(const AtomicString& localName);
   static bool shouldCreateCustomElement(const QualifiedName&);
 
-  static HTMLElement* createCustomElementSync(Document&,
-                                              const AtomicString& localName);
-  static HTMLElement* createCustomElementSync(Document&, const QualifiedName&);
+  static HTMLElement* createCustomElementSync(
+      Document&,
+      const AtomicString& localName,
+      const AtomicString& is = AtomicString());
+  static HTMLElement* createCustomElementSync(
+      Document&,
+      const QualifiedName&,
+      const AtomicString& is = AtomicString());
   static HTMLElement* createCustomElementAsync(Document&, const QualifiedName&);
 
   static HTMLElement* createFailedElement(Document&, const QualifiedName&);