Remove deprecated Strings class.

tools/test.dart

 #!/usr/bin/env 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.
 
 /**
  * This file is the entrypoint of the dart test suite.  This suite is used
  * to test:
  *
  *     1. the dart vm
@@ skipping 86 matching lines @@
   // Print the configurations being run by this execution of
   // test.dart. However, don't do it if the silent progress indicator
   // is used. This is only needed because of the junit tests.
   if (progressIndicator != 'silent') {
     List output_words = configurations.length > 1 ?
         ['Test configurations:'] : ['Test configuration:'];
     for (Map conf in configurations) {
       List settings = ['compiler', 'runtime', 'mode', 'arch']
           .mappedBy((name) => conf[name]).toList();
       if (conf['checked']) settings.add('checked');
-      output_words.add(Strings.join(settings, '_'));
+      output_words.add(settings.join('_'));
     }
-    print(Strings.join(output_words, ' '));
+    print(output_words.join(' '));
   }
 
   // Start global http servers that serve the entire dart repo.
   // The http server is available on window.location.port, and a second server
   // for cross-domain tests can be found by calling getCrossOriginPortNumber().
   if (!listTests) {
     // Only start the server if we are running browser tests.
     var runningBrowserTests = configurations.any((config) {
       return TestUtils.isBrowserRuntime(config['runtime']);
     });
@@ skipping 47 matching lines @@
   new ProcessQueue(maxProcesses,
                    maxBrowserProcesses,
                    progressIndicator,
                    startTime,
                    printTiming,
                    testSuites,
                    allTestsFinished,
                    verbose,
                    listTests);
 }