Fix a broken link.

lib/src/runner/configuration/args.dart

 // Copyright (c) 2016, 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:io';
 
 import 'package:args/args.dart';
 import 'package:boolean_selector/boolean_selector.dart';
 
 import '../../backend/test_platform.dart';
@@ skipping 77 matching lines @@
 
   parser.addSeparator("======== Output");
   parser.addOption("reporter",
       abbr: 'r',
       help: 'The runner used to print test results.',
       defaultsTo: defaultReporter,
       allowed: allReporters,
       allowedHelp: {
     'compact': 'A single line, updated continuously.',
     'expanded': 'A separate line for each update.',
-    'json': 'A machine-readable format (see https://goo.gl/0HRhdZ).'
+    'json': 'A machine-readable format (see https://goo.gl/gBsV1a).'
   });
   parser.addFlag("verbose-trace", negatable: false,
       help: 'Whether to emit stack traces with core library frames.');
   parser.addFlag("js-trace", negatable: false,
       help: 'Whether to emit raw JavaScript stack traces for browser tests.');
   parser.addFlag("color",
       help: 'Whether to use terminal colors.\n(auto-detected by default)');
 
   /// The following options are used only by the internal Google test runner.
   /// They're hidden and not supported as stable API surface outside Google.
@@ skipping 123 matching lines @@
   /// information.
   /*=T*/ _wrapFormatException/*<T>*/(String name, /*=T*/ parse()) {
     try {
       return parse();
     } on FormatException catch (error) {
       throw new FormatException('Couldn\'t parse --$name "${_options[name]}": '
           '${error.message}');
     }
   }
 }