dart2js: run dartfmt on tests

tests/compiler/dart2js/erroneous_element_test.dart

 // Copyright (c) 2012, 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 'package:expect/expect.dart';
 
-import 'package:compiler/src/diagnostics/messages.dart'
-    show MessageKind;
+import 'package:compiler/src/diagnostics/messages.dart' show MessageKind;
 import 'package:compiler/src/elements/elements.dart';
-import 'package:compiler/src/elements/modelx.dart'
-    show ErroneousElementX;
+import 'package:compiler/src/elements/modelx.dart' show ErroneousElementX;
 
 void main() {
-  ErroneousElement e = new ErroneousElementX(MessageKind.GENERIC,
-                                             {'text': 'error'},
-                                             'foo', null);
+  ErroneousElement e = new ErroneousElementX(
+      MessageKind.GENERIC, {'text': 'error'}, 'foo', null);
   Expect.stringEquals('<foo: error>', '$e');
 }