dart2js: run dartfmt on tests

tests/compiler/dart2js_extra/js_array_removeLast_error_test.dart

 // Copyright (c) 2015, 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.
 
 // Test that optimized JSArray removeLast() calls generate the same error as
 // dyncamically dispatched calls.
 
 import 'package:expect/expect.dart';
 
-@NoInline() @AssumeDynamic()
+@NoInline()
+@AssumeDynamic()
 confuse(x) => x;
 
-
 Error getError(action()) {
   try {
     action();
     Expect.fail('must throw');
   } catch (e) {
     return e;
   }
 }
 
 main() {
   fault1() {
     return confuse([]).removeLast();
   }
 
   fault2() {
     var a = [];
     while (confuse(false)) a.add(1);
     // This one should be optimized since [a] is a growable JSArray.
     return a.removeLast();
   }
 
   var e1 = getError(fault1);
   var e2 = getError(fault2);
 
   Expect.equals('$e1', '$e2');
 }