Add Zone support for Timers.

tests/lib/async/catch_errors2_test.dart

Index: tests/lib/async/catch_errors2_test.dart
diff --git a/tests/lib/async/catch_errors2_test.dart b/tests/lib/async/catch_errors2_test.dart
index e67d665019b5f67e1f5f77fc268d5fb4501526fa..3469fb84915dd0cce2052b61251b4d3b1066b5ba 100644
--- a/tests/lib/async/catch_errors2_test.dart
+++ b/tests/lib/async/catch_errors2_test.dart
@@ -8,7 +8,7 @@ import 'dart:isolate';
 
 main() {
   // We keep a ReceivePort open until all tests are done. This way the VM will
-  // time out if the callbacks are not invoked.
+  // hang if the callbacks are not invoked and the test will time out.
   var port = new ReceivePort();
   bool futureWasExecuted = false;
   // Make sure that `catchErrors` only closes the error stream when the inner
@@ -19,7 +19,7 @@ main() {
     });
     return 'allDone';
   }).listen((x) {
-      Expect.fail("Unexped callback");
+      Expect.fail("Unexpected callback");
     },
     onDone: () {
       Expect.isTrue(futureWasExecuted);