Wait for a timed-out test's tear-down logic.

lib/src/frontend/timeout.dart

 // Copyright (c) 2015, 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 test.frontend.timeout;
 
 /// A class representing a modification to the default timeout for a test.
 ///
 /// By default, a test will time out after 30 seconds. With [new Timeout], that
 /// can be overridden entirely; with [new Timeout.factor], it can be scaled
@@ skipping 41 matching lines @@
     return new Timeout.factor(scaleFactor * other.scaleFactor);
   }
 
   /// Returns a new [Duration] from applying [this] to [base].
   ///
   /// If this is [none], returns `null`.
   Duration apply(Duration base) {
     if (this == none) return null;
     return duration == null ? base * scaleFactor : duration;
   }
+
+  String toString() {
+    if (duration != null) return duration.toString();
+    if (scaleFactor != null) return "${scaleFactor}x";
+    return "none";
+  }
 }