Let unresolved custom element go through CustomElementCallbackQueue.

Source/core/dom/custom/CustomElementResolutionStep.cpp

Index: Source/core/dom/custom/CustomElementResolutionStep.cpp
diff --git a/Source/modules/mediastream/NavigatorUserMediaError.cpp b/Source/core/dom/custom/CustomElementResolutionStep.cpp
similarity index 77%
copy from Source/modules/mediastream/NavigatorUserMediaError.cpp
copy to Source/core/dom/custom/CustomElementResolutionStep.cpp
index e9cef28d55f28832dcf3cf43e3528dda82d29eec..24bc8d44d45ce46e5f24da72b160ceac1a339ffe 100644
--- a/Source/modules/mediastream/NavigatorUserMediaError.cpp
+++ b/Source/core/dom/custom/CustomElementResolutionStep.cpp
@@ -29,22 +29,21 @@
  */
 
 #include "config.h"
-#include "modules/mediastream/NavigatorUserMediaError.h"
+#include "core/dom/custom/CustomElementResolutionStep.h"
+
+#include "core/dom/Element.h"
+#include "core/dom/custom/CustomElementRegistrationContext.h"
 
 namespace WebCore {
 
-String NavigatorUserMediaError::name() const
+PassOwnPtr<CustomElementResolutionStep> CustomElementResolutionStep::create(const CustomElementDescriptor& descriptor)
 {
-    switch (m_name) {
-    case NamePermissionDenied:
-        return "PermissionDeniedError";
-
-    case NameConstraintNotSatisfied:
-        return "ConstraintNotSatisfiedError";
-    }
+    return adoptPtr(new CustomElementResolutionStep(descriptor));
+}
 
-    ASSERT_NOT_REACHED();
-    return String();
+void CustomElementResolutionStep::dispatch(Element* element)
+{
+    element->document().registrationContext()->resolve(element, m_descriptor);

[dominicc (has gone to gerrit), 2013/12/14 02:42:39]

Looking up the registration context this way will break if this sequence of
things happen:

1. Element is created => resolution scheduled.
2. Something moves element to a new document.
3. Processing queue reaches resolution step for element.

In this case the registration context could be different.

We should record the registration context in the resolution step.

[Hajime Morrita, 2013/12/16 09:00:34]

Done, added a test also.

 }
 
 } // namespace WebCore