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

tests/standalone/io/skipping_dart2js_compilations_test.dart

-// 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.
 
 /*
  * This test makes sure that the "skipping Dart2Js compilations if the output is
  * already up to date" feature does work as it should.
  * Therefore this test ensures that compilations are only skipped if the last
  * modified date of the output of a dart2js compilation is newer than
  *   - the the dart application to compile (including it's dependencies)
  *   - the dart2js snapshot
@@ skipping 85 matching lines @@
     return suite.TestUtils.absolutePath(new Path(tempDir.path)
         .append('test_dart2js.snapshot'));
   }
 
   void touchFile(File file) {
     _writeToFile(file, _readFile(file));
   }
 
   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();
     }
   }
 
   String _readFile(File file) {
     return file.readAsStringSync();
   }
 
   File _createFile(Path path) {
@@ skipping 122 matching lines @@
       cleanup();
       throw error;
     }).then((_) {
       cleanup();
     });
   }
   // We need to wait some time to make sure that the files we 'touch' get a
   // bigger timestamp than the old ones
   new Timer(new Duration(seconds: 1), touchFilesAndRunTests);
 }