Change all File APIs to make the mode and encoding arguments named

tests/standalone/io/skipping_dart2js_compilations_test.dart

Index: tests/standalone/io/skipping_dart2js_compilations_test.dart
diff --git a/tests/standalone/io/skipping_dart2js_compilations_test.dart b/tests/standalone/io/skipping_dart2js_compilations_test.dart
index c6ce377a277cda10e5f8b8eb865cbbfd894e0d71..a142ab394fa5e75071c7435c8086f7c5a094e382 100644
--- a/tests/standalone/io/skipping_dart2js_compilations_test.dart
+++ b/tests/standalone/io/skipping_dart2js_compilations_test.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
@@ -104,7 +104,7 @@ class FileUtils {
 
   void _writeToFile(File file, String content) {
     if (content != null) {
-      var fd = new File(file.fullPathSync()).openSync(FileMode.WRITE);
+      var fd = new File(file.fullPathSync()).openSync(mode: FileMode.WRITE);
       fd.writeStringSync(content);
       fd.closeSync();
     }