Fix HTTP support in vm-service

runtime/vm/service/running_isolates.dart

 // Copyright (c) 2013, 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 vmservice;
 
 class RunningIsolates implements MessageRouter {
   final Map<int, RunningIsolate> isolates = new Map<int, RunningIsolate>();
   int _rootPortId;
 
@@ skipping 15 matching lines @@
   }
 
   Future<String> route(Message message) {
     String isolateParam = message.params['isolateId'];
     int isolateId;
     if (!isolateParam.startsWith('isolates/')) {
       message.setErrorResponse('Malformed isolate id $isolateParam');
       return message.response;
     }
     isolateParam = isolateParam.substring('isolates/'.length);
-    if (isolateParam == 'isolates/root') {
+    if (isolateParam == 'root') {
       isolateId = _rootPortId;
     } else {
       try {
         isolateId = int.parse(isolateParam);
       } catch (e) {
         message.setErrorResponse('Could not parse isolate id: $e');
         return message.response;
       }
     }
     var isolate = isolates[isolateId];
     if (isolate == null) {
       message.setErrorResponse('Cannot find isolate id: $isolateId');
       return message.response;
     }
     return isolate.route(message);
   }
 }