Add Timer implementation for dart2js. Also moves tests to appropriate location.

tests/standalone/io/timer_repeat_test.dart

Index: tests/standalone/io/timer_repeat_test.dart
diff --git a/tests/standalone/io/timer_repeat_test.dart b/tests/standalone/io/timer_repeat_test.dart
deleted file mode 100644
index 26c409aae3dbe4157fd724ef742897368c5f9983..0000000000000000000000000000000000000000
--- a/tests/standalone/io/timer_repeat_test.dart
+++ /dev/null
@@ -1,41 +0,0 @@
-// 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.
-
-#import("dart:isolate");
-
-class TimerRepeatTest {
-
-  static final int _TIMEOUT = 500;
-  static final int _ITERATIONS = 5;
-
-  static void testRepeatTimer() {
-
-    void timeoutHandler(Timer timer) {
-      int endTime = (new Date.now()).millisecondsSinceEpoch;
-      _iteration++;
-      if (_iteration < _ITERATIONS) {
-        _startTime = (new Date.now()).millisecondsSinceEpoch;
-      } else {
-        Expect.equals(_iteration, _ITERATIONS);
-        timer.cancel();
-      }
-    }
-
-    _iteration = 0;
-    _startTime = (new Date.now()).millisecondsSinceEpoch;
-    timer = new Timer.repeating(_TIMEOUT, timeoutHandler);
-  }
-
-  static void testMain() {
-    testRepeatTimer();
-  }
-
-  static Timer timer;
-  static int _startTime;
-  static int _iteration;
-}
-
-main() {
-  TimerRepeatTest.testMain();
-}