Refactor Future constructors.

sdk/lib/io/link.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 dart.io;
 
 /**
  * [Link] objects are references to filesystem links.
  *
  */
@@ skipping 112 matching lines @@
   SendPort _fileService;
 
   _Link(String this.path);
 
   _Link.fromPath(Path inputPath) : path = inputPath.toNativePath();
 
   String toString() => "Link: '$path'";
 
   Future<bool> exists() {
     // TODO(whesse): Replace with asynchronous version.
-    return new Future.immediate(existsSync());
+    return new Future.value(existsSync());
   }
 
   bool existsSync() => FileSystemEntity.isLinkSync(path);
 
   Future<Link> create(String target) {
     _ensureFileService();
     if (Platform.operatingSystem == 'windows') {
       target = _makeWindowsLinkTarget(target);
     }
     List request = new List(3);
@@ skipping 54 matching lines @@
     });
   }
 
   void deleteSync() {
     var result = _File._deleteLink(path);
     throwIfError(result, "Cannot delete link '$path'");
   }
 
   Future<String> target() {
     // TODO(whesse): Replace with asynchronous version.
-    return new Future.of(targetSync);
+    return new Future.sync(targetSync);
   }
 
   String targetSync() {
     var result = _File._linkTarget(path);
     throwIfError(result, "Cannot read link '$path'");
     return result;
   }
 
   static throwIfError(Object result, String msg) {
     if (result is OSError) {
@@ skipping 47 matching lines @@
       if (path != null) {
         sb.write(", path = $path");
       }
     }
     return sb.toString();
   }
   final String message;
   final String path;
   final OSError osError;
 }