Remove Sink and move CollectionSink to async.

utils/pub/log.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.
 
 /// Message logging.
 library log;
 
 import 'dart:async';
 import 'io.dart';
 
@@ skipping 190 matching lines @@
 /// Log function that prints the message to stderr.
 void _logToStderr(Entry entry) {
   _logToStream(stderrSink, entry, showLabel: false);
 }
 
 /// Log function that prints the message to stderr with the level name.
 void _logToStderrWithLabel(Entry entry) {
   _logToStream(stderrSink, entry, showLabel: true);
 }
 
-void _logToStream(Sink<List<int>> sink, Entry entry, {bool showLabel}) {
+void _logToStream(StreamSink<List<int>> sink, Entry entry, {bool showLabel}) {
   bool firstLine = true;
   for (var line in entry.lines) {
     if (showLabel) {
       if (firstLine) {
         sink.add(entry.level.name.charCodes);
         sink.add(': '.charCodes);
       } else {
         sink.add('    | '.charCodes);
       }
     }
 
     sink.add(line.charCodes);
     sink.add('\n'.charCodes);
 
     firstLine = false;
   }
 }