dart2js: run dartfmt on tests

tests/compiler/dart2js_extra/deferred/deferred_overlapping_test.dart

 // Copyright (c) 2014, 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.
 
 import "deferred_overlapping_lib1.dart" deferred as lib1;
 import "deferred_overlapping_lib2.dart" deferred as lib2;
 
 // lib1.C1 and lib2.C2 has a shared base class It will go in its own hunk.
 // If lib1 or lib2s hunks are loaded before the common hunk, the program
 // will fail because the base class does not exist.
 void main() {
   lib1.loadLibrary().then((_) {
     var a = new lib1.C1();
     lib2.loadLibrary().then((_) {
       var b = new lib2.C2();
     });
   });
-}
+}