Remove deprecated StringBuffer.add, addAll and addCharCode.

samples/chat/chat_server_lib.dart

Index: samples/chat/chat_server_lib.dart
diff --git a/samples/chat/chat_server_lib.dart b/samples/chat/chat_server_lib.dart
index 5741417947238fc934bc7cd3dc32acc44930373a..628cd9a49c8ef74b0d7ade3659bbc8b3e7415f8c 100644
--- a/samples/chat/chat_server_lib.dart
+++ b/samples/chat/chat_server_lib.dart
@@ -377,7 +377,7 @@ class IsolatedServer {
   void _joinHandler(HttpRequest request, HttpResponse response) {
     StringBuffer body = new StringBuffer();
     request.listen(
-      (data) => body.add(new String.fromCharCodes(data)),
+      (data) => body.write(new String.fromCharCodes(data)),
       onDone: () {
         String data = body.toString();
         if (data != null) {
@@ -411,7 +411,7 @@ class IsolatedServer {
   void _leaveHandler(HttpRequest request, HttpResponse response) {
     StringBuffer body = new StringBuffer();
     request.listen(
-      (data) => body.add(new String.fromCharCodes(data)),
+      (data) => body.write(new String.fromCharCodes(data)),
       onDone: () {
         String data = body.toString();
         var requestData = json.parse(data);
@@ -441,7 +441,7 @@ class IsolatedServer {
   void _messageHandler(HttpRequest request, HttpResponse response) {
     StringBuffer body = new StringBuffer();
     request.listen(
-      (data) => body.add(new String.fromCharCodes(data)),
+      (data) => body.write(new String.fromCharCodes(data)),
       onDone: () {
         String data = body.toString();
         _messageCount++;
@@ -478,7 +478,7 @@ class IsolatedServer {
   void _receiveHandler(HttpRequest request, HttpResponse response) {
     StringBuffer body = new StringBuffer();
     request.listen(
-      (data) => body.add(new String.fromCharCodes(data)),
+      (data) => body.write(new String.fromCharCodes(data)),
       onDone: () {
         String data = body.toString();
         var requestData = json.parse(data);