Let unresolved custom element go through CustomElementCallbackQueue.

Source/core/dom/custom/CustomElementResolutionStep.h

Index: Source/core/dom/custom/CustomElementResolutionStep.h
diff --git a/Source/core/dom/custom/CustomElementException.h b/Source/core/dom/custom/CustomElementResolutionStep.h
similarity index 65%
copy from Source/core/dom/custom/CustomElementException.h
copy to Source/core/dom/custom/CustomElementResolutionStep.h
index 30bdb3be98179968f33a016aa009c75c66977d56..f077a7a9a30d2a632432cce5061de0670e002d7a 100644
--- a/Source/core/dom/custom/CustomElementException.h
+++ b/Source/core/dom/custom/CustomElementResolutionStep.h
@@ -28,40 +28,35 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef CustomElementException_h
-#define CustomElementException_h
+#ifndef CustomElementResolutionStep_h
+#define CustomElementResolutionStep_h
 
+#include "core/dom/custom/CustomElementDescriptor.h"
+#include "core/dom/custom/CustomElementProcessingStep.h"
+#include "wtf/PassOwnPtr.h"
 #include "wtf/text/AtomicString.h"
-#include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
-class ExceptionState;
+class CustomElementRegistrationContext;
 
-class CustomElementException {
+class CustomElementResolutionStep : public CustomElementProcessingStep {
+    WTF_MAKE_NONCOPYABLE(CustomElementResolutionStep);
 public:
-    enum Reason {
-        CannotRegisterFromExtension,
-        ConstructorPropertyNotConfigurable,
-        ContextDestroyedCheckingPrototype,
-        ContextDestroyedCreatingCallbacks,
-        ContextDestroyedRegisteringDefinition,
-        ExtendsIsInvalidName,
-        ExtendsIsCustomElementName,
-        InvalidName,
-        PrototypeInUse,
-        PrototypeNotAnObject,
-        TypeAlreadyRegistered
-    };
+    static PassOwnPtr<CustomElementResolutionStep> create(PassRefPtr<CustomElementRegistrationContext>, const CustomElementDescriptor&);
 
-    static void throwException(Reason, const AtomicString& type, ExceptionState&);
+    virtual ~CustomElementResolutionStep();
 
-private:
-    CustomElementException();
+protected:
+    CustomElementResolutionStep(PassRefPtr<CustomElementRegistrationContext>, const CustomElementDescriptor&);
+
+    virtual void dispatch(Element*) OVERRIDE;
 
-    static String preamble(const AtomicString& type);
+private:
+    RefPtr<CustomElementRegistrationContext> m_context;
+    CustomElementDescriptor m_descriptor;
 };
 
 }
 
-#endif // CustomElementException_h
+#endif // CustomElementResolutionStep_h