Update WATCHLISTS for Observatory

WATCHLISTS

 # 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.
 
 # Watchlist Rules
 # Refer: http://dev.chromium.org/developers/contributing-code/watchlists
 
 {
   'WATCHLIST_DEFINITIONS': {
     'runtime': {
       'filepath': 'runtime/',
     },
     'tools': {
       'filepath': 'tools/',
     },
+    'observatory': {
+      'filepath': 'runtime/bin/vmservice/',
+    },
   },
 
   'WATCHLISTS': {
     'runtime': ['vm-dev@dartlang.org'],
     'tools': ['ricow@google.com'],
+    'observatory': ['johnmccutchan@google.com', 'turnidge@google.com'],
   },
 }