Make FileInputStream and FileOutputStream actually asynchronous.

runtime/bin/string_stream.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 // Interface for decoders decoding binary data into string data. The
 // decoder keeps track of line breaks during decoding.
 interface _StringDecoder {
   // Add more binary data to be decoded. The ownership of the buffer
   // is transfered to the decoder and the caller most not modify it any more.
   int write(List<int> buffer);
 
@@ skipping 341 matching lines @@
         if (_clientCloseHandler !== null) _clientCloseHandler();
         _closed = true;
       }
     }
 
     if (!_closed) {
       // Schedule data callback if string data available.
       if (_clientDataHandler != null &&
           !_decoder.isEmpty() &&
           _scheduledDataCallback == null) {
-        if (_scheduledLineCallback != null) _scheduledLineCallback.cancel();
+        if (_scheduledLineCallback != null) {
+          _scheduledLineCallback.cancel();
+        }
         _scheduledDataCallback = new Timer(issueDataCallback, 0);
       }
 
       // Schedule line callback if a line is available.
       if (_clientLineHandler != null &&
           (_decoder.lineBreaks > 0 || (!_decoder.isEmpty() && _inputClosed)) &&
           _scheduledLineCallback == null) {
-        if (_scheduledDataCallback != null) _scheduledDataCallback.cancel();
+        if (_scheduledDataCallback != null) {
+          _scheduledDataCallback.cancel();
+        }
         _scheduledLineCallback = new Timer(issueLineCallback, 0);
       }
 
       // Schedule close callback if no more data and input is closed.
       if (_decoder.isEmpty() &&
           _inputClosed &&
           _scheduledCloseCallback == null) {
         _scheduledCloseCallback = new Timer(issueCloseCallback, 0);
       }
     }
   }
 
   InputStream _input;
   String _encoding;
   _StringDecoder _decoder;
   bool _inputClosed = false;  // Is the underlying input stream closed?
   bool _closed = false;  // Is this stream closed.
   bool _eof = false;  // Has all data been read from the decoder?
   Timer _scheduledDataCallback;
   Timer _scheduledLineCallback;
   Timer _scheduledCloseCallback;
   Function _clientDataHandler;
   Function _clientLineHandler;
   Function _clientCloseHandler;
 }