Refactor Future constructors.

utils/pub/validator/name.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.
 
 library name_validator;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:pathos/path.dart' as path;
@@ skipping 10 matching lines @@
   "new", "null", "return", "super", "switch", "this", "throw", "true", "try",
   "var", "void", "while", "with"
 ];
 
 /// A validator that validates the name of the package and its libraries.
 class NameValidator extends Validator {
   NameValidator(Entrypoint entrypoint)
     : super(entrypoint);
 
   Future validate() {
-    return new Future.of(() {
+    return new Future.sync(() {
       _checkName(entrypoint.root.name, 'Package name "${entrypoint.root.name}"',
           isPackage: true);
 
       var libraries = _libraries;
       for (var library in libraries) {
         var libName = path.basenameWithoutExtension(library);
         _checkName(libName, 'The name of "$library", "$libName",',
             isPackage: false);
       }
 
@@ skipping 48 matching lines @@
       builder
         ..write(source.substring(lastMatchEnd, match.start + 1))
         ..write("_")
         ..write(match.group(1).toLowerCase());
       lastMatchEnd = match.end;
     }
     builder.write(source.substring(lastMatchEnd));
     return builder.toString().toLowerCase();
   }
 }