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

tools/dom/templates/html/impl/impl_Element.darttemplate

 // 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 $LIBRARYNAME;
 
 // TODO(jacobr): use _Lists.dart to remove some of the duplicated
 // functionality.
 class _ChildrenElementList extends ListBase<Element> {
   // Raw Element.
@@ skipping 162 matching lines @@
 
   void remove(Object object) {
     if (object is Element) {
       Element element = object;
       if (identical(element.parentNode, _element)) {
         _element.$dom_removeChild(element);
       }
     }
   }
 
-  void removeAll(Iterable elements) {
-    _childElements.removeAll(elements);
-  }
-
-  void retainAll(Iterable elements) {
-    _childElements.retainAll(elements);
-  }
-
   void removeWhere(bool test(Element element)) {
     _childElements.removeWhere(test);
   }
 
   void retainWhere(bool test(Element element)) {
     _childElements.retainWhere(test);
   }
 
   void removeRange(int start, int rangeLength) {
     throw new UnimplementedError();
@@ skipping 141 matching lines @@
   }
 
   Element removeLast() {
     throw new UnsupportedError('');
   }
 
   void remove(Object element) {
     throw new UnsupportedError('');
   }
 
-  void removeAll(Iterable elements) {
-    throw new UnsupportedError('');
-  }
-
-  void retainAll(Iterable elements) {
-    throw new UnsupportedError('');
-  }
-
   void removeWhere(bool test(Element element)) {
     throw new UnsupportedError('');
   }
 
   void retainWhere(bool test(Element element)) {
     throw new UnsupportedError('');
   }
 
   Element get first => _nodeList.first;
 
@@ skipping 137 matching lines @@
    *
    * This set makes it easy to add, remove or toggle the classes applied to
    * this element.
    *
    *     element.classes.add('selected');
    *     element.classes.toggle('isOnline');
    *     element.classes.remove('selected');
    */
   CssClassSet get classes => new _ElementCssClassSet(this);
 
-  void set classes(Collection<String> value) {
+  void set classes(Iterable<String> value) {
     CssClassSet classSet = classes;
     classSet.clear();
     classSet.addAll(value);
   }
 
   /**
    * Allows access to all custom data attributes (data-*) set on this element.
    *
    * The keys for the map must follow these rules:
    *
@@ skipping 456 matching lines @@
   const ScrollAlignment._internal(this._value);
   toString() => 'ScrollAlignment.$_value';
 
   /// Attempt to align the element to the top of the scrollable area.
   static const TOP = const ScrollAlignment._internal('TOP');
   /// Attempt to center the element in the scrollable area.
   static const CENTER = const ScrollAlignment._internal('CENTER');
   /// Attempt to align the element to the bottom of the scrollable area.
   static const BOTTOM = const ScrollAlignment._internal('BOTTOM');
 }