Oilpan: move custom element objects to the heap.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index b69cf2e04871d5bcbfef8fe95af8bd0c5ba78658..6f282b6418bfa875abf79a7fd9de05ff8d2b097c 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -620,9 +620,9 @@ void Document::dispose()
     m_associatedFormControls.clear();
 
     detachParser();
-#endif
 
     m_registrationContext.clear();
+#endif
 
     if (m_importsController) {
         m_importsController->wasDetachedFrom(*this);
@@ -5787,6 +5787,7 @@ void Document::trace(Visitor* visitor)
     visitor->trace(m_contextFeatures);
     visitor->trace(m_styleSheetList);
     visitor->trace(m_mediaQueryMatcher);
+    visitor->trace(m_registrationContext);
     visitor->trace(m_associatedFormControls);
     visitor->trace(m_templateDocument);
     visitor->trace(m_templateDocumentHost);