Add Observatory test of io.

runtime/bin/service_object_patch.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.
 
 
 final Map _servicePathMap = {
   'http' : {
     'servers' : _httpServersServiceObject,
   },
   'sockets' : _socketsServiceObject,
   'websockets' : _webSocketsServiceObject,
   'file' : {
     'randomaccessfiles' : _randomAccessFilesServiceObject
   },
   'processes' : _processesServiceObject,
 };
 
+String _getServicePath(obj) => obj._servicePath;
+
 String _serviceObjectHandler(List<String> paths,
                              List<String> keys,
                              List<String> values) {
   assert(keys.length == values.length);
   if (paths.isEmpty) {
     return JSON.encode(_ioServiceObject());
   }
   int i = 0;
   var current = _servicePathMap;
   do {
@@ skipping 113 matching lines @@
     }
     return process._toJSON(false);
   }
   return {
     'id': 'io/processes',
     'type': 'ProcessList',
     'members': _ProcessImpl._processes.values
         .map((p) => p._toJSON(true)).toList(),
   };
 }