Remove usage of dart:json.

sdk/lib/_internal/pub/test/test_pub.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.
 
 /// Test infrastructure for testing pub. Unlike typical unit tests, most pub
 /// tests are integration tests that stage some stuff on the file system, run
 /// pub, and then validate the results. This library provides an API to build
 /// tests like that.
 library test_pub;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
-import 'dart:json' as json;
 import 'dart:math';
 
 import 'package:http/testing.dart';
 import 'package:path/path.dart' as path;
 import 'package:scheduled_test/scheduled_process.dart';
 import 'package:scheduled_test/scheduled_server.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:unittest/compact_vm_config.dart';
 
 import '../lib/src/entrypoint.dart';
@@ skipping 165 matching lines @@
         var name = spec['name'];
         var version = spec['version'];
         var versions = _servedPackages.putIfAbsent(name, () => []);
         versions.add(spec);
       }
 
       _servedApiPackageDir.contents.clear();
       _servedPackageDir.contents.clear();
       for (var name in _servedPackages.keys) {
         _servedApiPackageDir.contents.addAll([
-          d.file('$name', json.stringify({
+          d.file('$name', JSON.encode({
             'name': name,
             'uploaders': ['nweiz@google.com'],
             'versions': _servedPackages[name].map(packageVersionApiMap).toList()
           })),
           d.dir(name, [
             d.dir('versions', _servedPackages[name].map((pubspec) {
-              return d.file(pubspec['version'], json.stringify(
+              return d.file(pubspec['version'], JSON.encode(
                   packageVersionApiMap(pubspec, full: true)));
             }))
           ])
         ]);
 
         _servedPackageDir.contents.add(d.dir(name, [
           d.dir('versions', _servedPackages[name].map((pubspec) {
             var version = pubspec['version'];
             return d.tar('$version.tar.gz', [
-              d.file('pubspec.yaml', json.stringify(pubspec)),
+              d.file('pubspec.yaml', JSON.encode(pubspec)),
               d.libDir(name, '$name $version')
             ]);
           }))
         ]));
       }
     });
   }, 'initializing the package server');
 }
 
 /// Converts [value] into a YAML string.
-String yaml(value) => json.stringify(value);
+String yaml(value) => JSON.encode(value);
 
 /// The full path to the created sandbox directory for an integration test.
 String get sandboxDir => _sandboxDir;
 String _sandboxDir;
 
 /// The path of the package cache directory used for tests. Relative to the
 /// sandbox directory.
 final String cachePath = "cache";
 
 /// The path of the mock SDK directory used for tests. Relative to the sandbox
@@ skipping 494 matching lines @@
     failures.addAll(expected.map((line) => '| $line'));
     failures.add('Got:');
     failures.addAll(results);
   }
 }
 
 void _validateOutputJson(List<String> failures, String pipe,
                          expected, String actualText) {
   var actual;
   try {
-    actual = json.parse(actualText);
+    actual = JSON.decode(actualText);
   } on FormatException catch(error) {
     failures.add('Expected $pipe JSON:');
     failures.add(expected);
     failures.add('Got invalid JSON:');
     failures.add(actualText);
   }
 
   // Do a deep comparison of the JSON objects.
   expect(actual, equals(expected));
 }
@@ skipping 30 matching lines @@
   bool matches(item, Map matchState) {
     if (item is! Pair) return false;
     return _firstMatcher.matches(item.first, matchState) &&
         _lastMatcher.matches(item.last, matchState);
   }
 
   Description describe(Description description) {
     description.addAll("(", ", ", ")", [_firstMatcher, _lastMatcher]);
   }
 }