dart:io | Add asynchronous Link.create implementation.

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 106 matching lines @@
   String toString() => "Link: '$path'";
 
   Future<bool> exists() {
     // TODO(whesse): Replace with asynchronous version.
     return new Future.immediate(existsSync());
   }
 
   bool existsSync() => FileSystemEntity.isLinkSync(path);
 
   Future<Link> create(String target) {
-    // TODO(whesse): Replace with asynchronous version.
-    return new Future.of(() {
-      createSync(target);
+    _ensureFileService();
+    List request = new List(3);
+    request[0] = _CREATE_LINK_REQUEST;
+    request[1] = path;
+    request[2] = target;
+    return _fileService.call(request).then((response) {
+      if (_isErrorResponse(response)) {
+        throw _exceptionFromResponse(response,
+            "Cannot create link '$path' to target '$target'");
+      }
       return this;
     });
   }
 
   void createSync(String target) {
     if (Platform.operatingSystem == 'windows') {
       target = _makeWindowsLinkTarget(target);
     }
     var result = _File._createLink(path, target);
     throwIfError(result, "Cannot create link '$path'");
@@ skipping 106 matching lines @@
       if (path != null) {
         sb.write(", path = $path");
       }
     }
     return sb.toString();
   }
   final String message;
   final String path;
   final OSError osError;
 }