Rework Timer interface.

tests/standalone/io/skipping_dart2js_compilations_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.
 
 /*
  * This test makes sure that the "skipping Dart2Js compilations if the output is
  * already up to date" feature does work as it should.
  * Therefore this test ensures that compilations are only skipped if the last
  * modified date of the output of a dart2js compilation is newer than
  *   - the the dart application to compile (including it's dependencies)
@@ skipping 182 matching lines @@
                                               createSnapshot: true);
   var fs_notUpToDate_dart = new FileUtils(createJs: true,
                                           createJsDeps: true,
                                           createDart: true,
                                           createSnapshot: true);
   var fs_upToDate = new FileUtils(createJs: true,
                                   createJsDeps: true,
                                   createDart: true,
                                   createSnapshot: true);
 
-  void touchFilesAndRunTests(Timer unused) {
+  void touchFilesAndRunTests() {
     fs_notUpToDate_snapshot.touchFile(fs_notUpToDate_snapshot.testSnapshot);
     fs_notUpToDate_dart.touchFile(fs_notUpToDate_dart.testDart);
     fs_upToDate.touchFile(fs_upToDate.testJs);
 
     void runTest(String name, FileUtils fileUtils, bool shouldRun) {
       var testCase = makeTestCase(
           name, new TestCompletedHandler(fileUtils, shouldRun));
       new runner.RunningProcess(testCase, testCase.commands[0]).start();
     }
     runTest("fs_noTestJs", fs_noTestJs, true);
     runTest("fs_noTestJsDeps", fs_noTestJsDeps, true);
     runTest("fs_noTestDart", fs_noTestDart, true);
     runTest("fs_noTestSnapshot", fs_noTestSnapshot, true);
     runTest("fs_notUpToDate_snapshot", fs_notUpToDate_snapshot, true);
     runTest("fs_notUpToDate_dart", fs_notUpToDate_dart, true);
     // This is the only test where all dependencies are present and the test.js
     // file is newer than all the others. So we pass 'false' for shouldRun.
     runTest("fs_upToDate", fs_upToDate, false);
   }
   // We need to wait some time to make sure that the files we 'touch' get a
   // bigger timestamp than the old ones
-  new Timer(1000, touchFilesAndRunTests);
+  new Timer(new Duration(seconds: 1), touchFilesAndRunTests);
 }