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 e424d1f1399550161bff37c2e8d6f5504fa2ad30..3ac3ce485a4c676d6d7312284e8e092632ddbcc8 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -622,9 +622,9 @@ void Document::dispose()
     m_associatedFormControls.clear();
 
     detachParser();
-#endif
 
     m_registrationContext.clear();
+#endif
 
     if (m_importsController) {
         m_importsController->wasDetachedFrom(*this);
@@ -5778,6 +5778,7 @@ 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);