Fix a test which was broken by the previous revision.

test/runner/runner_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.
 
 @TestOn("vm")
 
 import 'dart:io';
 import 'dart:math' as math;
 
 import 'package:path/path.dart' as p;
@@ skipping 133 matching lines @@
 
     test("an annotation's structure is invalid", () {
       var testPath = p.join(_sandbox, "test.dart");
       new File(testPath).writeAsStringSync("@TestOn()\nlibrary foo;");
       var result = _runUnittest(["test.dart"]);
 
       expect(result.stdout, allOf([
         contains('-1: load error'),
         contains(
           '  Failed to load "${p.relative(testPath, from: _sandbox)}":\n'
-          "  Error on line 1, column 8: TestOn takes one argument.\n"
+          "  Error on line 1, column 8: TestOn takes 1 argument.\n"
           "  @TestOn()\n"
           "         ^^\n")
       ]));
       expect(result.exitCode, equals(1));
     });
 
     test("an annotation's contents are invalid", () {
       var testPath = p.join(_sandbox, "test.dart");
       new File(testPath).writeAsStringSync("@TestOn('zim')\nlibrary foo;");
       var result = _runUnittest(["test.dart"]);
@@ skipping 323 matching lines @@
       });
     });
   });
 }
 
 ProcessResult _runUnittest(List<String> args) =>
     runUnittest(args, workingDirectory: _sandbox);
 
 ProcessResult _runDart(List<String> args) =>
     runDart(args, workingDirectory: _sandbox);