Revert 24086 Update checked in binary to version 0.5.19.0

tools/testing/dart/test_progress.dart

 // Copyright (c) 2013, 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_progress;
 
 import "dart:io";
 import "dart:io" as io;
 import "http_server.dart" as http_server;
 import "status_file_parser.dart";
@@ skipping 155 matching lines @@
       var buf = new StringBuffer();
       for (var l in _buildFailureOutput(test)) {
         buf.write("$l\n");
       }
       _appendToFlakyFile(buf.toString());
     }
   }
 
   void _appendToFlakyFile(String msg) {
     var file = new File(TestUtils.flakyFileName());
-    var fd = file.openSync(mode: FileMode.APPEND);
+    var fd = file.openSync(FileMode.APPEND);
     fd.writeStringSync(msg);
     fd.closeSync();
   }
 }
 
 class SummaryPrinter extends EventListener {
   void allTestsKnown() {
     if (SummaryReport.total > 0) {
       SummaryReport.printReport();
     }
@@ skipping 333 matching lines @@
         print('@@@BUILD_STEP $stepName failures@@@');
       }
       for (String line in _failureSummary) {
         print(line);
       }
       print('');
     }
     print(_buildSummaryEnd(_failedTests));
   }
 }