Fixing type check error using Stream.take in dart2js checked mode.

sdk/lib/async/stream_pipe.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.async;
 
 /** Utility function to create an [AsyncError] if [error] isn't one already. */
 AsyncError _asyncError(Object error, Object stackTrace, [AsyncError cause]) {
   if (error is AsyncError) return error;
   if (cause == null) return new AsyncError(error, stackTrace);
@@ skipping 153 matching lines @@
     // If the transformation sends a done signal, we stop the subscription.
     if (_subscription != null) {
       _subscription.cancel();
       _subscription = null;
     }
     _onDone();
   }
 
   // Methods used as listener on source subscription.
 
-  void _handleData(S data) {
+  // TODO(ahe): Restore type when feature is implemented in dart2js
+  // checked mode. http://dartbug.com/7733
+  void _handleData(/*S*/ data) {
     _stream._handleData(data, this);
   }
 
   void _handleError(AsyncError error) {
     _stream._handleError(error, this);
   }
 
   void _handleDone() {
     _stream._handleDone(this);
   }
@@ skipping 317 matching lines @@
 /** Creates a [StreamSink] from a [_StreamImpl]'s input methods. */
 class _StreamImplSink<T> implements StreamSink<T> {
   _StreamImpl<T> _target;
   _StreamImplSink(this._target);
   void add(T data) { _target._add(data); }
   void signalError(AsyncError error) { _target._signalError(error); }
   void close() { _target._close(); }
 }