Fix typo.

sdk/lib/async/stream_controller.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;
 
 // -------------------------------------------------------------------
 // Controller for creating and adding events to a stream.
 // -------------------------------------------------------------------
 
@@ skipping 266 matching lines @@
  * on [Stream], and it must be used carefully to avoid doing so.
  *
  * The only advantage to using a [SynchronousStreamController] over a
  * normal [StreamController] is the improved latency.
  * Only use the synchronous version if the improvement is significant,
  * and if its use is safe. Otherwise just use a normal stream controller,
  * which will always have the correct behavior for a [Stream], and won't
  * accidentally break other code.
  *
  * Adding events to a synchronous controller should only happen as the
- * very last part of a the handling of the original event.
+ * very last part of the handling of the original event.
  * At that point, adding an event to the stream is equivalent to
  * returning to the event loop and adding the event in the next microtask.
  *
  * Each listener callback will be run as if it was a top-level event
  * or microtask. This means that if it throws, the error will be reported as
  * uncaught as soon as possible.
  * This is one reason to add the event as the last thing in the original event
  * handler - any action done after adding the event will delay the report of
  * errors in the event listener callbacks.
  *
@@ skipping 627 matching lines @@
   var varData;
 
   _StreamControllerAddStreamState(_StreamController<T> controller, this.varData,
       Stream source, bool cancelOnError)
       : super(controller, source, cancelOnError) {
     if (controller.isPaused) {
       addSubscription.pause();
     }
   }
 }