Remove usage of dart:json.

pkg/docgen/lib/docgen.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.
 
 /**
  * **docgen** is a tool for creating machine readable representations of Dart
  * code metadata, including: classes, members, comments and annotations.
  *
  * docgen is run on a `.dart` file or a directory containing `.dart` files.
  *
  *      $ dart docgen.dart [OPTIONS] [FILE/DIR]
  *
  * This creates files called `docs/<library_name>.yaml` in your current
  * working directory.
  */
 library docgen;
 
+import 'dart:convert';
 import 'dart:io';
-import 'dart:json';
 import 'dart:async';
 
 import 'package:logging/logging.dart';
 import 'package:markdown/markdown.dart' as markdown;
 import 'package:path/path.dart' as path;
 
 import 'dart2yaml.dart';
 import 'src/io.dart';
 import '../../../sdk/lib/_internal/compiler/compiler.dart' as api;
 import '../../../sdk/lib/_internal/compiler/implementation/filenames.dart';
@@ skipping 216 matching lines @@
   var filteredEntities = entityMap.values.where(_isVisible);
   
   // Outputs a JSON file with all libraries and their preview comments. 
   // This will help the viewer know what libraries are available to read in.
   var libraryMap;
   if (append) {
     var docsDir = listDir('docs');
     if (!docsDir.contains('docs/library_list.json')) {
       throw new StateError('No library_list.json');
     }
-    libraryMap = parse(new File('docs/library_list.json').readAsStringSync());
+    libraryMap =
+        JSON.decode(new File('docs/library_list.json').readAsStringSync());
     libraryMap['libraries'].addAll(filteredEntities
         .where((e) => e is Library)
         .map((e) => e.previewMap));
     if (introduction.isNotEmpty) {
       var intro = libraryMap['introduction'];
       if (intro.isNotEmpty) intro += '<br/><br/>';
       intro += markdown.markdownToHtml(
           new File(introduction).readAsStringSync(), 
               linkResolver: linkResolver, inlineSyntaxes: markdownSyntaxes);
       libraryMap['introduction'] = intro;
     }
     outputToYaml = libraryMap['filetype'] == 'yaml';
   } else {
     libraryMap = {
       'libraries' : filteredEntities.where((e) => 
           e is Library).map((e) => e.previewMap).toList(),
       'introduction' : introduction == '' ? 
           '' : markdown.markdownToHtml(new File(introduction)
               .readAsStringSync(), linkResolver: linkResolver, 
                   inlineSyntaxes: markdownSyntaxes), 
       'filetype' : outputToYaml ? 'yaml' : 'json'
     };
   }
-  _writeToFile(stringify(libraryMap), 'library_list.json');
+  _writeToFile(JSON.encode(libraryMap), 'library_list.json');
   // Output libraries and classes to file after all information is generated.
   filteredEntities.where((e) => e is Class || e is Library).forEach((output) {
     _writeIndexableToFile(output, outputToYaml);
   });
   // Outputs all the qualified names documented with their type.
   // This will help generate search results.
   _writeToFile(filteredEntities.map((e) => 
       '${e.qualifiedName} ${e.typeName}').join('\n'),
       'index.txt', append: append);
 }
 
 Library generateLibrary(dart2js.Dart2JsLibraryMirror library) {
   _currentLibrary = library;
   var result = new Library(library.qualifiedName, _commentToHtml(library),
       _variables(library.variables),
       _methods(library.functions),
       _classes(library.classes), _isHidden(library));
   logger.fine('Generated library for ${result.name}');
   return result;
 }
 
 void _writeIndexableToFile(Indexable result, bool outputToYaml) {
   if (outputToYaml) {
     _writeToFile(getYamlString(result.toMap()), '${result.qualifiedName}.yaml');
   } else {
-    _writeToFile(stringify(result.toMap()), '${result.qualifiedName}.json');
+    _writeToFile(JSON.encode(result.toMap()), '${result.qualifiedName}.json');
   }
 }
 
 /**
  * Returns true if a library name starts with an underscore, and false
  * otherwise.
  *
  * An example that starts with _ is _js_helper.
  * An example that contains ._ is dart._collection.dev
  */
@@ skipping 75 matching lines @@
 
 /**
  * Generates MDN comments from database.json. 
  */
 void _mdnComment(Indexable item) {
   //Check if MDN is loaded. 
   if (_mdn == null) {
     // Reading in MDN related json file. 
     var mdnDir = path.join(path.dirname(path.dirname(path.dirname(path.dirname(
         path.absolute(new Options().script))))), 'utils', 'apidoc', 'mdn');
-    _mdn = parse(new File(path.join(mdnDir, 'database.json'))
+    _mdn = JSON.decode(new File(path.join(mdnDir, 'database.json'))
         .readAsStringSync());
   }
   if (item.comment.isNotEmpty) return;
   var domAnnotation = item.annotations.firstWhere(
       (e) => e.qualifiedName == 'metadata.DomName', orElse: () => null);
   if (domAnnotation == null) return;
   var domName = domAnnotation.parameters.single;
   var parts = domName.split('.');
   if (parts.length == 2) item.comment = _mdnMemberComment(parts[0], parts[1]);
   if (parts.length == 1) item.comment = _mdnTypeComment(parts[0]);
@@ skipping 759 matching lines @@
   String qualifiedName;
   List<String> parameters;
 
   Annotation(this.qualifiedName, this.parameters);
 
   Map toMap() => {
     'name': qualifiedName,
     'parameters': parameters
   };
 }