Code review changes for ngeoffray's comments on r28278

tools/dom/src/dart2js_CustomElementSupport.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.dom.html;
 
 _callConstructor(constructor) {
   return (receiver) {
     return JS('', '#(#)', constructor, receiver);
   };
@@ skipping 44 matching lines @@
   //    });
   //    document.register('x-foo', { prototype: proto });
   //    ...
   //    var e = document.createElement('x-foo');
 
   var interceptorClass = findInterceptorConstructorForType(type);
   if (interceptorClass == null) {
     throw new ArgumentError(type);
   }
 
-  var constructor = findConstructorForWebComponentType(type, 'created');
+  var constructor = findConstructorForNativeSubclassType(type, 'created');
   if (constructor == null) {
     throw new ArgumentError("$type has no constructor called 'created'");
   }
 
   // Workaround for 13190- use an article element to ensure that HTMLElement's
   // interceptor is resolved correctly.
   getNativeInterceptor(new Element.tag('article'));
 
   String baseClassName = findDispatchTagForInterceptorClass(interceptorClass);
   if (baseClassName == null) {
@@ skipping 36 matching lines @@
     }
   }
 
   JS('void', '#.register(#, #)', document, tag, options);
 }
 
 //// Called by Element.created to do validation & initialization.
 void _initializeCustomElement(Element e) {
   // TODO(blois): Add validation that this is only in response to an upgrade.
 }