Make IOSink implement StringSink

tests/standalone/io/http_proxy_test.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.
 
 import "dart:async";
 import "dart:io";
 import "dart:uri";
 
 class Server {
   HttpServer server;
@@ skipping 31 matching lines @@
         }
         var body = new StringBuffer();
         request.listen(
             (data) {
               body.add(new String.fromCharCodes(data));
             },
             onDone: () {
               String path = request.uri.path.substring(1);
               String content = "$path$path$path";
               Expect.equals(content, body.toString());
-              response.addString(request.uri.path);
+              response.write(request.uri.path);
               response.close();
             });
       });
       return x.future;
     });
   }
 
   void shutdown() {
     server.close();
   }
@@ skipping 95 matching lines @@
     client.findProxy = (Uri uri) {
       int index = int.parse(uri.path.substring(1));
       return proxy[index];
     };
 
     for (int i = 0; i < proxy.length; i++) {
       client.getUrl(Uri.parse("http://127.0.0.1:${server.port}/$i"))
         .then((HttpClientRequest clientRequest) {
           String content = "$i$i$i";
           clientRequest.contentLength = content.length;
-          clientRequest.addString(content);
+          clientRequest.write(content);
           return clientRequest.close();
         })
        .then((HttpClientResponse response) {
           response.listen((_) {}, onDone: () {
             testDirectDoneCount++;
             if (testDirectDoneCount == proxy.length) {
               Expect.equals(proxy.length, server.requestCount);
               server.shutdown();
               client.close();
             }
@@ skipping 38 matching lines @@
 
     for (int i = 0; i < proxy.length; i++) {
       test(bool secure) {
         String url = secure
             ? "https://localhost:${secureServer.port}/$i"
             : "http://127.0.0.1:${server.port}/$i";
 
         client.postUrl(Uri.parse(url))
           .then((HttpClientRequest clientRequest) {
             String content = "$i$i$i";
-            clientRequest.addString(content);
+            clientRequest.write(content);
             return clientRequest.close();
           })
           .then((HttpClientResponse response) {
             response.listen((_) {}, onDone: () {
               testProxyDoneCount++;
               if (testProxyDoneCount == proxy.length * 2) {
                 Expect.equals(proxy.length, server.requestCount);
                 proxyServer.shutdown();
                 server.shutdown();
                 secureServer.shutdown();
@@ skipping 45 matching lines @@
       // Pick the proxy configuration based on the request path.
       int index = int.parse(uri.path.substring(1));
       return proxy[index];
     };
 
     for (int i = 0; i < proxy.length; i++) {
       client.getUrl(Uri.parse("http://127.0.0.1:${server.port}/$i"))
         .then((HttpClientRequest clientRequest) {
           String content = "$i$i$i";
           clientRequest.contentLength = content.length;
-          clientRequest.addString(content);
+          clientRequest.write(content);
           return clientRequest.close();
         })
         .then((HttpClientResponse response) {
           response.listen((_) {}, onDone: () {
             testProxyChainDoneCount++;
             if (testProxyChainDoneCount == proxy.length) {
               Expect.equals(proxy.length, server.requestCount);
               proxyServer1.shutdown();
               proxyServer2.shutdown();
               server.shutdown();
@@ skipping 22 matching lines @@
       // Pick the proxy configuration based on the request path.
       int index = int.parse(uri.path.substring(1));
       return proxy[index];
     };
 
     for (int i = 0; i < proxy.length; i++) {
       client.getUrl(Uri.parse("http://127.0.0.1:${server.port}/$i"))
         .then((HttpClientRequest clientRequest) {
           String content = "$i$i$i";
           clientRequest.contentLength = content.length;
-          clientRequest.addString(content);
+          clientRequest.write(content);
           return clientRequest.close();
         })
         .then((HttpClientResponse response) {
           response.listen((_) {}, onDone: () {
             testRealProxyDoneCount++;
             if (testRealProxyDoneCount == proxy.length) {
               Expect.equals(proxy.length, server.requestCount);
               server.shutdown();
               client.close();
             }
@@ skipping 13 matching lines @@
 main() {
   InitializeSSL();
   testInvalidProxy();
   testDirectProxy();
   testProxy();
   testProxyChain();
   // This test is not normally run. It can be used for locally testing
   // with a real proxy server (e.g. Apache).
   //testRealProxy();
 }