Fix static type warnings in test.dart.

client/tests/dartc/test_config.dart

 // Copyright (c) 2011, 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.
 
 #library("client_dartc_test_config");
 
 #import("../../../tools/testing/dart/test_suite.dart");
 
 class ClientDartcTestSuite extends DartcCompilationTestSuite {
   ClientDartcTestSuite(Map configuration)
       : super(configuration,
               "dartc",
               "client",
               ['async',
                'base',
                'box2d',
                'dom',
                'json',
                'observable',
                'samples',
                'streams',
                'testing',
                'tests',
                'touch',
                'util',
                'view',
                'weld'],
               ["client/tests/dartc/dartc.status"]);
 
-  void isTestFile(String filename) {
+  bool isTestFile(String filename) {
     if (!filename.endsWith(".dart")) return false;
     var options = optionsFromFile(filename);
     return optionsFromFile(filename)["containsLeadingHash"];
   }
 
-  void listRecursively() => true;
+  bool listRecursively() => true;
 }