catchErrors and waitForCompletion now based on runZonedExperimental.

tests/lib/async/run_zoned3_test.dart

Index: tests/lib/async/run_zoned3_test.dart
diff --git a/tests/lib/async/catch_errors10_test.dart b/tests/lib/async/run_zoned3_test.dart
similarity index 52%
copy from tests/lib/async/catch_errors10_test.dart
copy to tests/lib/async/run_zoned3_test.dart
index 573ecc80e79f19f90f59fec41e75eb735e4e2b4e..f8802084f56b200477dc040da4d33ddb98754c0d 100644
--- a/tests/lib/async/catch_errors10_test.dart
+++ b/tests/lib/async/run_zoned3_test.dart
@@ -10,21 +10,17 @@ main() {
   // We keep a ReceivePort open until all tests are done. This way the VM will
   // hang if the callbacks are not invoked and the test will time out.
   var port = new ReceivePort();
-  bool futureWasExecuted = false;
-  // Test that `catchErrors` waits for a future that has been delayed by
-  // `Timer.run`.
-  catchErrors(() {
-    Timer.run(() {
-      new Future.value(499).then((x) {
-        futureWasExecuted = true;
-      });
-    });
-    return 'allDone';
-  }).listen((x) {
-      Expect.fail("Unexpected callback");
-    },
-    onDone: () {
-      Expect.isTrue(futureWasExecuted);
-      port.close();
-    });
+  // Ensure that `runZoned` is done when a synchronous call throws.
+  bool sawException = false;
+  try {
+    runZonedExperimental(() { throw 0; },
+                         onDone: () {
+                           // onDone is executed synchronously.
+                           Expect.isFalse(sawException);
+                           port.close();
+                         });
+  } catch (e) {
+    sawException = true;
+  }
+  Expect.isTrue(sawException);
 }