Make custom element name checks faster and fewer

third_party/WebKit/Source/build/scripts/templates/ElementFactory.h.tmpl

 {% from "macros.tmpl" import license %}
 {{ license() }}
 
 #ifndef {{namespace}}ElementFactory_h
 #define {{namespace}}ElementFactory_h
 
 #include "core/dom/Document.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/PassRefPtr.h"
 
 namespace blink {
 
 class Document;
 class {{namespace}}Element;
 {% if namespace == 'HTML' %}
+class ExceptionState;
 class HTMLFormElement;
 {% endif %}
 
 class {{namespace}}ElementFactory {
 public:
     static {{namespace}}Element* create{{namespace}}Element(
         const AtomicString& localName,
         Document&,
         {% if namespace == 'HTML' %}
         HTMLFormElement* = 0,
+        ExceptionState* = 0,

[kouhei (in TOK), 2016/08/29 06:59:55]

nullptr

         {% endif %}
         CreateElementFlags flags = CreatedByParser);
 };
 
 } // namespace blink
 
 #endif