Revert "Revert "Basic functionality is working with JS native support and polyfill, still some issu…

tests/html/custom/constructor_calls_created_synchronously_test.dart

Index: tests/html/custom/constructor_calls_created_synchronously_test.dart
diff --git a/tests/html/custom/constructor_calls_created_synchronously_test.dart b/tests/html/custom/constructor_calls_created_synchronously_test.dart
index 77b5446bb7ddbd4aff60a3459d6932ab92ed0c42..f383a7aa51d3024384e7c12755b1d9b58410d1ed 100644
--- a/tests/html/custom/constructor_calls_created_synchronously_test.dart
+++ b/tests/html/custom/constructor_calls_created_synchronously_test.dart
@@ -18,12 +18,26 @@ class A extends HtmlElement {
   }
 }
 
+loadPolyfills() {
+  if (!document.supportsRegister) {
+    // Cache blocker is a workaround for:
+    // https://code.google.com/p/dart/issues/detail?id=11834
+    var cacheBlocker = new DateTime.now().millisecondsSinceEpoch;
+    return HttpRequest.getString('/root_dart/pkg/custom_element/lib/'
+      'custom-elements.debug.js?cacheBlock=$cacheBlocker').then((code) {
+      document.head.children.add(new ScriptElement()..text = code);
+    });
+  }
+}
+
 main() {
   useHtmlConfiguration();
 
   // Adapted from Blink's
   // fast/dom/custom/constructor-calls-created-synchronously test.
 
+  setUp(loadPolyfills);
+
   test('createdCallback', () {
     document.register(A.tag, A);
     var x = new A();