Add persistent handles to service protocol and Observatory UI

runtime/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;
 
 // Some value smaller than the object ring, so requesting a large array
 // doesn't result in an expired ref because the elements lapped it in the
 // object ring.
 const int kDefaultFieldLimit = 100;
@@ skipping 1175 matching lines @@
   Future<Class> getClassHierarchy() {
     return invokeRpc('getClassList', {})
         .then(_loadClasses)
         .then(_buildClassHierarchy);
   }
 
   Future<ServiceObject> getPorts() {
     return invokeRpc('_getPorts', {});
   }
 
+  Future<ServiceObject> getPersistentHandles() {
+    return invokeRpc('_getPersistentHandles', {});
+  }
+
   Future<List<Class>> getClassRefs() async {
     ServiceMap classList = await invokeRpc('getClassList', {});
     assert(classList.type == 'ClassList');
     var classRefs = [];
     for (var cls in classList['classes']) {
       // Skip over non-class classes.
       if (cls is Class) {
         _classesByCid[cls.vmCid] = cls;
         classRefs.add(cls);
       }
@@ skipping 2770 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);
     }
   }
 }