Remove usage of dart:json.

samples/newissues/newissues.dart

 // Copyright (c) 2012, 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:html';
-import 'dart:json' as jsonlib;
+import "dart:convert";
 
 /// Issue wraps JSON structure that describes a bug.
 class Issue {
   final json;
   Issue(this.json);
 
   void addTo(Element div) {
     div.children.add(new Element.tag("h2")..text = json[r"title"][r"$t"]);
     div.children.add(new Element.tag("p")..text = json[r"content"][r"$t"]);
   }
 }
 
 /// Decodes JSON into a list of Issues.
 List<Issue> getIssues(json) {
   var issues = json["feed"]["entry"];
   if (issues == null) return null;
   return issues.map((data) => new Issue(data)).toList();
 }
 
 /// Iterates over the received issues and construct HTML for them.
 void processJson(String jsonText) {
-  var json = jsonlib.parse(jsonText);
+  var json = JSON.decode(jsonText);
   Element div = query("#content");
   List<Issue> list = getIssues(json);
   if (list == null) {
     div.children.add(new Element.tag("h2")..text = "... no issues found.");
   } else {
     list.forEach((Issue i) => i.addTo(div));
   }
 }
 
 /// Sends a HTTPRequest and returns a future for the data.
 Future<dynamic> requestJson(String url) {
   Completer c = new Completer<dynamic>();
   void callback(HttpRequest req) {
     if (req.readyState == HttpRequest.DONE) {
-      c.complete(jsonlib.parse(req.response));
+      c.complete(JSON.decode(req.response));
     }
   };
   return HttpRequest.getString(url);
 }
 
 void main() {
   // Requests new issues from the Dart issue database as json.
   const String url = "https://code.google.com/feeds/issues/p/dart/issues/full";
   const String options = "alt=json&can=new";
   requestJson("$url?$options").then(processJson);
 }