Improve the instance-view page in observatory.

runtime/bin/vmservice/client/lib/src/elements/instance_ref.dart

Index: runtime/bin/vmservice/client/lib/src/elements/instance_ref.dart
diff --git a/runtime/bin/vmservice/client/lib/src/elements/instance_ref.dart b/runtime/bin/vmservice/client/lib/src/elements/instance_ref.dart
index bdbf8e50568595b8301a67fac8e6efd76abfc1ab..c97e484dfc70b75ff96a5fa4b1021d0934dd3eb6 100644
--- a/runtime/bin/vmservice/client/lib/src/elements/instance_ref.dart
+++ b/runtime/bin/vmservice/client/lib/src/elements/instance_ref.dart
@@ -38,15 +38,17 @@ class InstanceRefElement extends ServiceRefElement {
 
   void expandEvent(bool expand, var done) {
     assert(ref is ServiceMap);
-    ServiceMap refMap = ref;
     if (expand) {
-      refMap.reload().then((_) {
-        if (refMap['preview'] != null) {
-          refMap.name = refMap['preview'];
-          refMap.vmName = refMap['preview'];
+      ref.reload().then((result) {
+        if (result['preview'] != null) {
+          result.name = result['preview'];
+          result.vmName = result['preview'];
         }
+        ref = result;
+        notifyPropertyChange(#ref, 0, 1);
       }).whenComplete(done);
     } else {
+      ServiceMap refMap = ref;
       refMap['fields'] = null;
       refMap['elements'] = null;
       done();