Rename unsubscribe to cancel.

sdk/lib/io/file_impl.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.
 
 part of dart.io;
 
 class _FileInputStream extends _BaseDataInputStream implements InputStream {
   _FileInputStream(String name)
       : _data = const [],
         _position = 0,
@@ skipping 558 matching lines @@
   }
 
   Stream<List<int>> openForRead() {
     return new _InputStreamController(new _FileInputStream(_name)).stream;
   }
 
   Future<StreamSink<List<int>>> openForWrite([FileMode mode = FileMode.WRITE]) {
     return open(mode).then((file) {
       var controller = new StreamController();
 
-      var subscription = controller.subscribe();
-      subscription.onData((data) {
-        // TODO(ajohnsen): handle errors correctly.
-        file.writeList(data, 0, data.length);
-      });
-      subscription.onDone(file.close);
+      var subscription = controller.listen(
+        (data) {
+          // TODO(ajohnsen): handle errors correctly.
+          file.writeList(data, 0, data.length);
+        },
+        onDone: file.close);
 
       return controller.sink;
     });
   }
 
   Future<List<int>> readAsBytes() {
     _ensureFileService();
     Completer<List<int>> completer = new Completer<List<int>>();
     var chunks = new _BufferList();
     var stream = openInputStream();
@@ skipping 578 matching lines @@
           new FileIOException("File closed '$_name'"));
     });
     return completer.future;
   }
 
   final String _name;
   int _id;
 
   SendPort _fileService;
 }