Remove Sink and move CollectionSink to async.

Committed: https://code.google.com/p/dart/source/detail?r=18063
Reverted: https://code.google.com/p/dart/source/detail?r=18067

Review URL: https://codereview.chromium.org//12154006

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@18144 260f80e4-7a28-3924-810f-c04153c831b5

lib/src/log.dart

@@ -208,7 +208,7 @@ 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) {