Revert 20969: Reduce usage of IterableMixinWorkaround

sdk/lib/collection/queue.dart

 // Copyright (c) 2011, 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.collection;
 
 /**
  * A [Queue] is a collection that can be manipulated at both ends. One
  * can iterate over the elements of a queue through [forEach] or with
  * an [Iterator].
@@ skipping 206 matching lines @@
     while (!identical(entry, _sentinel)) {
       if (entry.element == o) {
         entry.remove();
         _elementCount--;
         return;
       }
       entry = entry._next;
     }
   }
 
-  void retainAll(Iterable elements) {
-    _filterIterable(elements, true);
+  void removeAll(Iterable elements) {
+    // Use this method when remove is slow and removeWhere more efficient.
+    IterableMixinWorkaround.removeAllList(this, elements);
   }
 
-  void removeAll(Iterable elements) {
-    _filterIterable(elements, false);
-  }
-
-  void _filterIterable(Iterable elements, bool retainMatching) {
-    Set elementSet;
-    if (elements is Set) {
-      elementSet = elements;
-    } else {
-      elementSet = elements.toSet();
-    }
-    _filter(elementSet.contains, retainMatching);
-  }
-
-  void _filter(bool test(E element), bool retainMatching) {
+  void removeWhere(bool test(E element)) {
     DoubleLinkedQueueEntry<E> entry = firstEntry();
     while (!identical(entry, _sentinel)) {
       DoubleLinkedQueueEntry<E> next = entry._next;
-      if (test(entry.element) != retainMatching) {
+      if (test(entry.element)) {
         entry.remove();
         _elementCount--;
       }
       entry = next;
     }
   }
 
-  void removeWhere(bool test(E element)) {
-    _filter(test, false);
-  }
-
   void retainWhere(bool test(E element)) {
-    _filter(test, true);
+    DoubleLinkedQueueEntry<E> entry = firstEntry();
+    while (!identical(entry, _sentinel)) {
+      DoubleLinkedQueueEntry<E> next = entry._next;
+      if (!test(entry.element)) {
+        entry.remove();
+        _elementCount--;
+      }
+      entry = next;
+    }
   }
 
   E get first {
     return _sentinel._next.element;
   }
 
   E get last {
     return _sentinel._previous.element;
   }
 
@@ skipping 443 matching lines @@
     _queue._checkModification(_modificationCount);
     if (_position == _end) {
       _current = null;
       return false;
     }
     _current = _queue._table[_position];
     _position = (_position + 1) & (_queue._table.length - 1);
     return true;
   }
 }