Make incremental tests time out faster.

dart/tests/try/web/sandbox.dart

 // Copyright (c) 2014, 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.
 
 /// Helper library that creates an iframe sandbox that can be used to load
 /// code.
 library trydart.test.sandbox;
 
 import 'dart:html';
 import 'dart:async';
@@ skipping 65 matching lines @@
   // stackoverflow.
   installErrorHandlerOn(iframe);
   return iframe;
 }
 
 class Listener {
   Completer completer;
 
   String expectedMessage;
 
+  Stopwatch wallclock;
+
+  int get elapsed => wallclock.elapsedMilliseconds ~/ 1000;
+
   void onMessage(MessageEvent e) {
     String message = e.data;
     if (expectedMessage == message) {
       completer.complete();
     } else {
       switch (message) {
         case 'dart-calling-main':
         case 'dart-main-done':
         case 'unittest-suite-done':
         case 'unittest-suite-fail':
@@ skipping 14 matching lines @@
       completer = new Completer();
       return completer.future;
     } else if (data is Iterable) {
       return Future.forEach(data, expect);
     } else {
       throw 'Unexpected data type: ${data.runtimeType}.';
     }
   }
 
   void start() {
+    wallclock = new Stopwatch()..start();
     window.onMessage.listen(onMessage);
   }
 }