Code review changes for ngeoffray's comments on r28278

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index f72e8f79ee0d19089ef4eb5cacdd94fb50c4e679..bd1ddf9327f140c1adfbaa9f4078e755312f44a3 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -56,7 +56,7 @@ import 'dart:_js_helper' show
     makeLeafDispatchRecord;
 import 'dart:_interceptors' show
     Interceptor, JSExtendableArray, findInterceptorConstructorForType,
-    findConstructorForWebComponentType, getNativeInterceptor,
+    findConstructorForNativeSubclassType, getNativeInterceptor,
     setDispatchProperty, findInterceptorForType;
 
 export 'dart:math' show Rectangle, Point;
@@ -32423,7 +32423,7 @@ void _registerCustomElement(context, document, String tag, Type type,
     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'");
   }