Fix bug in DoubleLinkedQueue where removing from empty queue throws.

sdk/lib/core/annotations.dart

 // Copyright (c) 2013, 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.core;
 
 /**
  * The annotation `@Deprecated('expires when')` marks a feature as deprecated.
  *
  * The annotation `@deprecated` is a shorthand for deprecating until
- * to an unspecified "next release".
+ * an unspecified "next release".
  *
  * The intent of the `@Deprecated` annotation is to inform users of a feature
  * that they should change their code, even if it is currently still working
  * correctly.
  *
  * A deprecated feature is scheduled to be removed at a later time, possibly
  * specified as the "expires" field of the annotation.
  * This means that a deprecated feature should not be used, or code using it
  * will break at some point in the future. If there is code using the feature,
  * that code should be rewritten to not use the deprecated feature.
@@ skipping 111 matching lines @@
  *
  * Tools that understand `@proxy` should tell the user if a class using `@proxy`
  * does not override the `noSuchMethod` declared on [Object].
  *
  * The intent of the `@proxy` notation is to create objects that implement a
  * type (or multiple types) that are not known at compile time. If the types
  * are known at compile time, a class can be written that implements these
  * types.
  */
 const Object proxy = const _Proxy();