Make dartdoc and apidoc run on the VM instead of node.

utils/apidoc/html_diff.dart

 // Copyright (c) 2011, 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.
 
 /**
  * A script to assist in documenting the difference between the dart:html API
  * and the old DOM API.
  */
 #library('html_diff');
 
 #import('dart:coreimpl');
 #import('../../frog/lang.dart');
-#import('../../frog/file_system_node.dart');
+#import('../../frog/file_system_vm.dart');
 #import('../../frog/file_system.dart');
 #import('../dartdoc/dartdoc.dart');
 
 /**
  * A class for computing a many-to-many mapping between the types and members in
  * `dart:dom` and `dart:html`. This mapping is based on two indicators:
  *
  *   1. Auto-detected wrappers. Most `dart:html` types correspond
  *      straightforwardly to a single `dart:dom` type, and have the same name.
  *      In addition, most `dart:htmlimpl` methods just call a single `dart:dom`
@@ skipping 370 matching lines @@
   Map<String, String> _getTags(String comment) {
     if (comment == null) return const <String>{};
     final re = new RegExp("@([a-zA-Z]+) ([^;]+)(?:;|\$)");
     final tags = <String>{};
     for (var m in re.allMatches(comment.trim())) {
       tags[m[1]] = m[2];
     }
     return tags;
   }
 }