Added support for logging the output of failed flaky tests.

tools/test-runtime.dart

 #!/usr/bin/env dart
 // Copyright (c) 2012, 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.
 
 // TODO(ager): Get rid of this version of test.dart when we don't have
 // to worry about the special runtime checkout anymore.
 // This file is identical to test.dart with test suites in the
 // directories samples, client, compiler, and utils removed.
 
 #library("test");
 
 #import("dart:io");
+#import("testing/dart/test_progress.dart");
 #import("testing/dart/test_runner.dart");
 #import("testing/dart/test_options.dart");
 #import("testing/dart/test_suite.dart");
 #import("testing/dart/http_server.dart");
 
 #import("../tests/co19/test_config.dart");
 #import("../runtime/tests/vm/test_config.dart");
 
 /**
  * The directories that contain test suites which follow the conventions
@@ skipping 19 matching lines @@
   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 listTests = firstConf['list'];
-
+  var appendFlakyLog = firstConf['append_flaky_log'];
+  
+  if (!appendFlakyLog)  {
+    var file = new File(FAILED_FLAKY_TESTS_LOGFILE);
+    if (file.existsSync()) {
+      file.deleteSync();
+    }
+  }
   // Print the configurations being run by this execution of
   // test.dart. However, don't do it if the silent progress indicator
   // is used. This is only needed because of the junit tests.
   if (progressIndicator != 'silent') {
     List output_words = configurations.length > 1 ?
         ['Test configurations:'] : ['Test configuration:'];
     for (Map conf in configurations) {
       List settings =
           ['compiler', 'runtime', 'mode', 'arch'].map((name) => conf[name]);
       if (conf['checked']) settings.add('checked');
@@ skipping 40 matching lines @@
   new ProcessQueue(
       maxProcesses,
       progressIndicator,
       startTime,
       printTiming,
       enqueueConfiguration,
       () => terminateHttpServer(),
       verbose,
       listTests);
 }