Suppressing first-chance exception in path_observer.

pkg/observe/lib/src/path_observer.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 observe;
 
 // This code is inspired by ChangeSummary:
 // https://github.com/rafaelw/ChangeSummary/blob/master/change_summary.js
 // ...which underlies MDV. Since we don't need the functionality of
 // ChangeSummary, we just implement what we need for data bindings.
@@ skipping 27 matching lines @@
    * See [PathObserver.bindSync] and [PathObserver.value].
    */
   PathObserver(Object object, String path)
       : path = path,
         _isValid = _isPathValid(path),
         _segments = <Object>[] {
 
     if (_isValid) {
       for (var segment in path.trim().split('.')) {
         if (segment == '') continue;
-        var index = int.parse(segment, onError: (_) => null);
+        var index = int.parse(segment, radix: 10, onError: (_) => null);
         _segments.add(index != null ? index : new Symbol(segment));
       }
     }
 
     // Initialize arrays.
     // Note that the path itself can't change after it is initially
     // constructed, even though the objects along the path can change.
     _values = new List<Object>(_segments.length + 1);
     _values[0] = object;
     _subs = new List<StreamSubscription>(_segments.length);
@@ skipping 175 matching lines @@
 
 final _spacesRegExp = new RegExp(r'\s');
 
 bool _isPathValid(String s) {
   s = s.replaceAll(_spacesRegExp, '');
 
   if (s == '') return true;
   if (s[0] == '.') return false;
   return _pathRegExp.hasMatch(s);
 }