VM restart + shutdown fixes

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;
 
 /// Helper function for canceling a Future<StreamSubscription>.
 Future cancelFutureSubscription(
     Future<StreamSubscription> subscriptionFuture) async {
   if (subscriptionFuture != null) {
@@ skipping 785 matching lines @@
     });
   }
 
   void _dispatchEventToIsolate(ServiceEvent event) {
     var isolate = event.isolate;
     if (isolate != null) {
       isolate._onEvent(event);
     }
   }
 
+  Future restart() {
+    return invokeRpc('_restartVM', {});
+  }
+
   Future<ObservableMap> _fetchDirect() async {
     if (!loaded) {
       // The vm service relies on these events to keep the VM and
       // Isolate types up to date.
       await listenEventStream(kIsolateStream, _dispatchEventToIsolate);
       await listenEventStream(kDebugStream, _dispatchEventToIsolate);
       await listenEventStream(_kGraphStream, _dispatchEventToIsolate);
     }
     return await invokeRpcNoUpgrade('getVM', {});
   }
@@ skipping 3112 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);
     }
   }
 }