Add --time option to dart test scripts.

tools/test.dart

 #!/usr/bin/env dart
 // Copyright (c) 2011, 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");
 
 #import("testing/dart/test_runner.dart");
 #import("testing/dart/test_options.dart");
 
@@ skipping 18 matching lines @@
   var optionsParser = new TestOptionsParser();
   List<Map> configurations = optionsParser.parse(new Options().arguments);
   if (configurations == null) return;
 
   // Extract global options from first configuration.
   var firstConf = configurations[0];
   Map<String, RegExp> selectors = firstConf['selectors'];
   var maxProcesses = firstConf['tasks'];
   var progressIndicator = firstConf['progress'];
   var verbose = firstConf['verbose'];
+  var printTiming = firstConf['time'];
 
   var configurationIterator = configurations.iterator();
   bool enqueueConfiguration(ProcessQueue queue) {
     if (!configurationIterator.hasNext()) {
       return false;
     }
 
     var conf = configurationIterator.next();
     if (selectors.containsKey('samples')) {
       queue.addTestSuite(new SamplesTestSuite(conf));
@@ skipping 42 matching lines @@
     }
 
     return true;
   }
 
   // Start process queue.
   var queue = new ProcessQueue(maxProcesses,
                                progressIndicator,
                                verbose,
                                startTime,
+                               printTiming,
                                enqueueConfiguration);
 }