Remove Collection, Collections and clean up List/Set/Queue implementations of retain/remove.

samples/swarm/Views.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 swarmlib;
 
 // This file contains View framework classes.
 // As it grows, it may need to be split into multiple files.
 
 /** A factory that creates a view from a data model. */
@@ skipping 152 matching lines @@
   }
 
   void onSelectedItemChange() {
     // TODO(rnystrom): use Observable to track the last value of _selectedItem
     // rather than tracking it ourselves.
     _select(findIndex(_lastSelectedItem), false);
     _select(findIndex(_selectedItem.value), true);
     _lastSelectedItem = _selectedItem.value;
   }
 
-  Collection<View> get childViews {
+  Iterable<View> get childViews {
     return _itemViews.values.toList();
   }
 
   void _onClick(MouseEvent e) {
     int index = _findAssociatedIndex(e.target);
     if (index != null) {
       _selectedItem.value = _data[index];
     }
   }
 
@@ skipping 791 matching lines @@
 
     container = node.query('.dialog-body');
     container.nodes.add(_content.node);
 
     return node;
   }
 
   /** Override to handle dialog done. */
   void onDone() { }
 }