Update pub to use the latest dart:io stream APIs.

utils/tests/pub/oauth2_test.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.
 
 library oauth2_test;
 
 import 'dart:io';
 import 'dart:json' as json;
 import 'dart:uri';
 
@@ skipping 54 matching lines @@
     var pub = startPubLish(server);
     confirmPublish(pub);
 
     server.handle('POST', '/token', (request, response) {
       return new ByteStream(request).toBytes().then((bytes) {
         var body = new String.fromCharCodes(bytes);
         expect(body, matches(
             new RegExp(r'(^|&)refresh_token=refresh\+token(&|$)')));
 
         response.headers.contentType = new ContentType("application", "json");
-        response.addString(json.stringify({
+        response.write(json.stringify({
           "access_token": "new access token",
           "token_type": "bearer"
         }));
         response.close();
       });
     });
 
     server.handle('GET', '/packages/versions/new.json', (request, response) {
       expect(request.headers.value('authorization'),
           equals('Bearer new access token'));
@@ skipping 66 matching lines @@
     var server = new ScheduledServer();
     credentialsFile(server, 'access token').scheduleCreate();
     var pub = startPubLish(server);
 
     confirmPublish(pub);
 
     server.handle('GET', '/packages/versions/new.json', (request, response) {
       response.statusCode = 401;
       response.headers.set('www-authenticate', 'Bearer error="invalid_token",'
           ' error_description="your token sucks"');
-      response.addString(json.stringify({
+      response.write(json.stringify({
         'error': {'message': 'your token sucks'}
       }));
       response.close();
     });
 
     expectLater(pub.nextErrLine(), equals('OAuth2 authorization failed (your '
         'token sucks).'));
     // TODO(rnystrom): The confirm line is run together with this one because
     // in normal usage, the user will have entered a newline on stdin which
     // gets echoed to the terminal. Do something better here?
@@ skipping 30 matching lines @@
   handleAccessTokenRequest(server, accessToken);
 }
 
 void handleAccessTokenRequest(ScheduledServer server, String accessToken) {
   server.handle('POST', '/token', (request, response) {
     return new ByteStream(request).toBytes().then((bytes) {
       var body = new String.fromCharCodes(bytes);
       expect(body, matches(new RegExp(r'(^|&)code=access\+code(&|$)')));
 
       response.headers.contentType = new ContentType("application", "json");
-      response.addString(json.stringify({
+      response.write(json.stringify({
         "access_token": accessToken,
         "token_type": "bearer"
       }));
       response.close();
     });
   });
 }