Remove usage of dart:json.

pkg/polymer/lib/deploy.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.
 
 /**
  * Temporary deploy command used to create a version of the app that can be
  * compiled with dart2js and deployed. This library should go away once `pub
  * deploy` can be configured to run barback transformers.
  *
  * From an application package you can run this program by calling dart with a
  * 'package:' url to this file:
  *
  *    dart package:polymer/deploy.dart
  */
 library polymer.deploy;
 
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
-import 'dart:json' as json;
 
 import 'package:barback/barback.dart';
 import 'package:path/path.dart' as path;
 import 'package:polymer/src/transform.dart' show phases;
 import 'package:stack_trace/stack_trace.dart';
 import 'package:yaml/yaml.dart';
 import 'package:args/args.dart';
 
 main() {
   var args = _parseArgs();
@@ skipping 145 matching lines @@
 Map<String, String> _packageDirs = () {
   var pub = path.join(path.dirname(new Options().executable),
       Platform.isWindows ? 'pub.bat' : 'pub');
   var result = Process.runSync(pub, ['list-package-dirs']);
   if (result.exitCode != 0) {
     print("unexpected error invoking 'pub':");
     print(result.stdout);
     print(result.stderr);
     exit(result.exitCode);
   }
-  var map = json.parse(result.stdout)["packages"];
+  var map = JSON.decode(result.stdout)["packages"];
   map.forEach((k, v) { map[k] = path.dirname(v); });
   map[_currentPackage] = '.';
   return map;
 }();
 
 /**
  * Internal packages used by polymer which we can copy directly to the output
  * folder without having to process them with barback.
  */
 // TODO(sigmund): consider computing this list by recursively parsing
@@ skipping 24 matching lines @@
     print(e.message);
     _showUsage(parser);
     return null;
   }
 }
 
 _showUsage(parser) {
   print('Usage: dart package:polymer/deploy.dart [options]');
   print(parser.getUsage());
 }