Added json result of test output to output debug directory.

tools/testing/dart/utils.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.
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:convert';
 import 'dart:math' as math;
 
 import 'configuration.dart';
@@ skipping 426 matching lines @@
   /// will be written to this file.
   ///
   /// This is useful for debugging flaky tests. When running on a buildbot, the
   /// file can be made visible in the waterfall UI.
   static const flakyFileName = ".flaky.log";
 
   /// If test.py was invoked with '--write-test-outcome-log it will write
   /// test outcomes to this file.
   static const testOutcomeFileName = ".test-outcome.log";
 
+  /// If test.py was invoked with '--write-result-log it will write
+  /// test outcomes to this file in the '--output-directory'.
+  static const resultLogFileName = "result.log";
+
   static void ensureExists(String filename, Configuration configuration) {
     if (!configuration.listTests && !existsCache.doesFileExist(filename)) {
       throw "'$filename' does not exist";
     }
   }
 
   static Path absolutePath(Path path) {
     if (!path.isAbsolute) {
       return currentWorkingDirectory.join(path);
     }
@@ skipping 72 matching lines @@
       }
       if (path.length > WINDOWS_SHORTEN_PATH_LIMIT) {
         ++shortNameCounter;
         var pathEnd = path.substring(path.length - WINDOWS_PATH_END_LENGTH);
         path = "short${shortNameCounter}_$pathEnd";
       }
     }
     return path;
   }
 }