Revert 149589 "Set a bit on Custom Elements on creation to simplify wrapping"

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index 4b0e2561499ba05ec9f2aeb4d75f7806dccc99b3..7cecc78af3275047d33f576a7ae1f9d5e2997a6a 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -2779,12 +2779,6 @@ bool Node::isUserActionElementFocused() const
     return document()->userActionElements().isFocused(this);
 }
 
-void Node::setIsCustomElement()
-{
-    ASSERT(isHTMLElement() || isSVGElement());
-    setFlag(IsCustomElement);
-}
-
 } // namespace WebCore
 
 #ifndef NDEBUG