Make _FileSystemWatcher.watch private.

runtime/bin/file_patch.dart

 // Copyright (c) 2012, 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.
 
 patch class _File {
   /* patch */ static _exists(String path) native "File_Exists";
   /* patch */ static _create(String path) native "File_Create";
   /* patch */ static _createLink(String path, String target)
       native "File_CreateLink";
   /* patch */ static _linkTarget(String path) native "File_LinkTarget";
@@ skipping 46 matching lines @@
   static final Map<int, _WatcherPath> _idMap = {};
 
   final String _path;
   final int _events;
   final bool _recursive;
 
   _WatcherPath _watcherPath;
 
   StreamController _broadcastController;
 
-  /* patch */ static Stream<FileSystemEvent> watch(
+  /* patch */ static Stream<FileSystemEvent> _watch(
       String path, int events, bool recursive) {
     if (Platform.isLinux) {
       return new _InotifyFileSystemWatcher(path, events, recursive).stream;
     }
     if (Platform.isWindows) {
       return new _Win32FileSystemWatcher(path, events, recursive).stream;
     }
     if (Platform.isMacOS) {
       return new _FSEventStreamFileSystemWatcher(
           path, events, recursive).stream;
@@ skipping 283 matching lines @@
   void _pathWatchedEnd() {
     _subscription.cancel();
     _controller.close();
   }
 }
 
 
 Uint8List _makeUint8ListView(Uint8List source, int offsetInBytes, int length) {
   return new Uint8List.view(source.buffer, offsetInBytes, length);
 }