remove xtag from Polymer

pkg/polymer/test/events_test.dart

Index: pkg/polymer/test/events_test.dart
diff --git a/pkg/polymer/test/events_test.dart b/pkg/polymer/test/events_test.dart
index cc803397ef71e0e1153f1a491f27dd5f88c36e1f..afd7e46787fc661897567b84f41f642b3c0b0168 100644
--- a/pkg/polymer/test/events_test.dart
+++ b/pkg/polymer/test/events_test.dart
@@ -39,21 +39,21 @@ main() {
     // Note: this test is currently the only event in
     // polymer/test/js/events.js at commit #7936ff8
     var testA = query('#a');
-    expect(testA.xtag.clicks, isEmpty);
+    expect(testA.clicks, isEmpty);
     testA.click();
-    expect(testA.xtag.clicks, ['host click on: test-a (id a)']);
+    expect(testA.clicks, ['host click on: test-a (id a)']);
   });
 
   test('local event', () {
     var testB = query('#b');
-    expect(testB.xtag.clicks, isEmpty);
+    expect(testB.clicks, isEmpty);
     testB.click();
-    expect(testB.xtag.clicks, []);
+    expect(testB.clicks, []);
     var b1 = testB.shadowRoot.query('#b-1');
     b1.click();
-    expect(testB.xtag.clicks, []);
+    expect(testB.clicks, []);
     var b2 = testB.shadowRoot.query('#b-2');
     b2.click();
-    expect(testB.xtag.clicks, ['local click under test-b (id b) on b-2']);
+    expect(testB.clicks, ['local click under test-b (id b) on b-2']);
   });
 }