Fix build and compile to JS.

runtime/bin/vmservice/observatory/lib/src/service/object.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of service;
 
 /// A [ServiceObject] is an object known to the VM service and is tied
 /// to an owning [Isolate].
 abstract class ServiceObject extends Observable {
   static int LexicalSortName(ServiceObject o1, ServiceObject o2) {
@@ skipping 1445 matching lines @@
   @reflectable final subclasses = new ObservableList<Class>();
 
   bool get canCache => true;
   bool get immutable => false;
 
   Class._empty(ServiceObjectOwner owner) : super._empty(owner);
 
   void _update(ObservableMap map, bool mapIsRef) {
     name = map['name'];
     vmName = (map.containsKey('vmName') ? map['vmName'] : name);
+    var idPrefix = "classes/";
+    assert(id.startsWith(idPrefix));
+    vmCid = int.parse(id.substring(idPrefix.length));
 
     if (mapIsRef) {
       return;
     }
 
     // We are fully loaded.
     _loaded = true;
 
     // Extract full properties.
     _upgradeCollection(map, isolate);
@@ skipping 27 matching lines @@
     functions.clear();
     functions.addAll(map['functions']);
     functions.sort(ServiceObject.LexicalSortName);
 
     superclass = map['super'];
     // Work-around Object not tracking its subclasses in the VM.
     if (superclass != null && superclass.name == "Object") {
       superclass._addSubclass(this);
     }
     error = map['error'];
-    var idPrefix = "classes/";
-    assert(id.startsWith(idPrefix));
-    vmCid = int.parse(id.substring(idPrefix.length));
 
     var allocationStats = map['allocationStats'];
     if (allocationStats != null) {
       newSpace.update(allocationStats['new']);
       oldSpace.update(allocationStats['old']);
       promotedByLastNewGC.instances = allocationStats['promotedInstances'];
       promotedByLastNewGC.bytes = allocationStats['promotedBytes'];
     }
   }
 
@@ skipping 1209 matching lines @@
     var v = list[i];
     if ((v is ObservableMap) && _isServiceMap(v)) {
       list[i] = owner.getFromMap(v);
     } else if (v is ObservableList) {
       _upgradeObservableList(v, owner);
     } else if (v is ObservableMap) {
       _upgradeObservableMap(v, owner);
     }
   }
 }