Use 'print' to send responses/notifications to the client.

pkg/analysis_server/lib/src/server/stdio_server.dart

Index: pkg/analysis_server/lib/src/server/stdio_server.dart
diff --git a/pkg/analysis_server/lib/src/server/stdio_server.dart b/pkg/analysis_server/lib/src/server/stdio_server.dart
index 6eab23018ffa870447a8968cf57f28a6dc55970d..8730d6f076eb4c9555b291c9238e53e77d86f62b 100644
--- a/pkg/analysis_server/lib/src/server/stdio_server.dart
+++ b/pkg/analysis_server/lib/src/server/stdio_server.dart
@@ -5,7 +5,6 @@
 library stdio.server;
 
 import 'dart:async';
-import 'dart:io';
 
 import 'package:analysis_server/src/channel/byte_stream_channel.dart';
 import 'package:analysis_server/src/socket_server.dart';
@@ -34,10 +33,8 @@ class StdioAnalysisServer {
    * Return a future that will be completed when stdin closes.
    */
   Future serveStdio() {
-    ByteStreamServerChannel serverChannel = new ByteStreamServerChannel(
-        stdin,
-        stdout.nonBlocking,
-        socketServer.instrumentationService);
+    PrintServerChannel serverChannel =
+        new PrintServerChannel(socketServer.instrumentationService);
     socketServer.createAnalysisServer(serverChannel);
     return serverChannel.closed;
   }