Rename Timer.repeating to Timer.periodic.

tests/isolate/timer_cancel_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.
 
 library timer_cancel_test;
 
 import 'dart:async';
 import 'dart:isolate';
 import '../../pkg/unittest/lib/unittest.dart';
 
@@ skipping 15 matching lines @@
       repeatTimer++;
       timer.cancel();
       expect(repeatTimer, 1);
     }
 
     cancelTimer = new Timer(ms * 1000, expectAsync0(unreachable, count: 0));
     cancelTimer.cancel();
     new Timer(ms * 1000, expectAsync0(handler));
     cancelTimer = new Timer(ms * 2000, expectAsync0(unreachable, count: 0));
     repeatTimer = 0;
-    new Timer.repeating(ms * 1500, expectAsync1(repeatHandler));
+    new Timer.periodic(ms * 1500, expectAsync1(repeatHandler));
   });
 
   test("cancel timer with same time", () {
     var t2;
     var t1 = new Timer(ms * 0, expectAsync0(() => t2.cancel()));
     t2 = new Timer(ms * 0, expectAsync0(t1.cancel, count: 0));
   });
 }