Converted Observatory refs elements

runtime/observatory/tests/observatory_ui/pc_descriptors_ref/element_test.dart

Index: runtime/observatory/tests/observatory_ui/pc_descriptors_ref/element_test.dart
diff --git a/runtime/observatory/tests/observatory_ui/class_ref/element_test.dart b/runtime/observatory/tests/observatory_ui/pc_descriptors_ref/element_test.dart
similarity index 54%
copy from runtime/observatory/tests/observatory_ui/class_ref/element_test.dart
copy to runtime/observatory/tests/observatory_ui/pc_descriptors_ref/element_test.dart
index 41aeb10f3d6ae1904271442cb5ec399cdc196e0f..ec10960829577561f85c8d2f34a3693954c457a8 100644
--- a/runtime/observatory/tests/observatory_ui/class_ref/element_test.dart
+++ b/runtime/observatory/tests/observatory_ui/pc_descriptors_ref/element_test.dart
@@ -4,27 +4,25 @@
 
 import 'dart:html';
 import 'package:unittest/unittest.dart';
-import 'package:observatory/src/elements/class_ref.dart';
+import 'package:observatory/src/elements/sentinel_value.dart';
 import '../mocks.dart';
 
 main() {
-  ClassRefElement.tag.ensureRegistration();
+  SentinelValueElement.tag.ensureRegistration();
 
-  const isolate = const IsolateRefMock();
-  const cls = const ClassRefMock();
+  const sentinel = const Sentinel();
   test('instantiation', () {
-    final e = new ClassRefElement(isolate, cls);
+    final e = new SentinelValueElement(sentinel);
     expect(e, isNotNull, reason: 'element correctly created');
-    expect(e.isolate, equals(isolate));
-    expect(e.cls, equals(cls));
+    expect(e.sentinel, equals(sentinel));
   });
   test('elements created after attachment', () async {
-    final e = new ClassRefElement(isolate, cls);
+    final e = new SentinelValueElement(sentinel);
     document.body.append(e);
     await e.onRendered.first;
-    expect(e.children.length, isNonZero, reason: 'has elements');
+    expect(e.text, isNotEmpty, reason: 'has text');
+    expect(e.title, isNotEmpty, reason: 'has title');
     e.remove();
     await e.onRendered.first;
-    expect(e.children.length, isZero, reason: 'is empty');
   });
 }