Add isolate tag-profile and better handling of errors

runtime/bin/vmservice/client/lib/src/service/service.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;
 
 /// Recursively upgrades all [ServiceObject]s inside [collection] which must
 /// be an [ObservableMap] or an [ObservableList]. Upgraded elements will be
 /// associated with [vm] and [isolate].
 void upgradeCollection(collection, VM vm, Isolate isolate) {
@@ skipping 26 matching lines @@
     } else if (v is ObservableMap) {
       _upgradeObservableMap(v, vm, isolate);
     }
   }
 }
 
 /// Upgrades response ([m]) from [vm] and [isolate] to a [ServiceObject].
 /// This acts like a factory which consumes an ObservableMap and returns
 /// a fully upgraded ServiceObject.
 ServiceObject _upgradeToServiceObject(VM vm, Isolate isolate, ObservableMap m) {
-  if (m == null) {
-    return null;
-  }
-  if (!ServiceObject.isServiceMap(m)) {
-    Logger.root.severe("Malformed service object: $m");
-  }
   assert(ServiceObject.isServiceMap(m));
   var type = ServiceObject.stripRef(m['type']);
+  // ServiceError and ServiceExceptions are handled before we attempt
+  // to upgrade.
+  assert(type != 'ServiceError');
+  assert(type != 'ServiceException');
   switch (type) {
     case 'Error':
       if (isolate != null) {
-        return new ServiceError.fromMap(isolate, m);
+        return new DartError.fromMap(isolate, m);
       } else {
-        return new ServiceError.fromMap(vm, m);
+        return new DartError.fromMap(vm, m);
       }
       break;
     case 'Script':
       return isolate.scripts.putIfAbsent(m);
     case 'Code':
       return isolate.codes.putIfAbsent(m);
     case 'Isolate':
       return vm.isolates.getIsolateFromMap(m);
     case 'Class':
       return isolate.classes.putIfAbsent(m);
     case 'Function':
       return isolate.functions.putIfAbsent(m);
     case 'VM':
       return vm.update(m);
   }
   return new ServiceMap.fromMap(isolate, m);
 }