Make IOSink implement StringSink

utils/tests/pub/test_pub.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 /// Test infrastructure for testing pub. Unlike typical unit tests, most pub
 /// tests are integration tests that stage some stuff on the file system, run
 /// pub, and then validate the results. This library provides an API to build
 /// tests like that.
 library test_pub;
 
 import 'dart:async';
@@ skipping 102 matching lines @@
           } catch (e) {
             response.statusCode = 404;
             response.contentLength = 0;
             response.close();
             return;
           }
 
           stream.toBytes().then((data) {
             response.statusCode = 200;
             response.contentLength = data.length;
-            response.add(data);
+            response.writeBytes(data);
             response.close();
           }).catchError((e) {
             print("Exception while handling ${request.uri}: $e");
             response.statusCode = 500;
             response.reasonPhrase = e.message;
             response.close();
           });
         });
         _portCompleter.complete(_server.port);
         _scheduleCleanup((_) => _closeServer());
@@ skipping 1297 matching lines @@
       return timeout(_stderrFuture.then((stream) => stream.toList())
               .then((lines) => lines.join("\n")),
           _SCHEDULE_TIMEOUT,
           "waiting for the last stderr line from process $name");
     });
   }
 
   /// Writes [line] to the process as stdin.
   void writeLine(String line) {
     _schedule((_) => _processFuture.then(
-        (p) => p.stdin.add('$line\n'.codeUnits)));
+        (p) => p.stdin.writeln('$line')));
   }
 
   /// Kills the process, and waits until it's dead.
   void kill() {
     _endScheduled = true;
     _schedule((_) {
       _endExpected = true;
       _process.kill();
       timeout(_exitCodeFuture, _SCHEDULE_TIMEOUT,
           "waiting for process $name to die");
@@ skipping 180 matching lines @@
 /// calling [completion] is unnecessary.
 void expectLater(Future actual, matcher, {String reason,
     FailureHandler failureHandler, bool verbose: false}) {
   _schedule((_) {
     return actual.then((value) {
       expect(value, matcher, reason: reason, failureHandler: failureHandler,
           verbose: false);
     });
   });
 }