Revert "Revert "Start of dartium custom element lifecycle event support.""

tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate

Index: tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate b/tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate
index a29e0c1c14235259431cb1eb87a7afb30c8e0043..08e370962fb7bb9870ab715da9241a7e027f993b 100644
--- a/tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate
+++ b/tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate
@@ -242,13 +242,13 @@ $endif
    * * VideoElement
    */
 $if DART2JS
-  void register(String tag, Type customElementClass, {String nativeTagName}) {
+  void register(String tag, Type customElementClass, {String extendsTag}) {
     _registerCustomElement(JS('', 'window'), this, tag, customElementClass,
-        nativeTagName);
+        extendsTag);
   }
 $else
-  void register(String tag, Type customElementClass, {String nativeTagName}) {
-    _Utils.register(tag, customElementClass);
+  void register(String tag, Type customElementClass, {String extendsTag}) {
+    _Utils.register(this, tag, customElementClass, extendsTag);
   }
 $endif