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

tools/dom/src/WrappedList.dart

Index: tools/dom/src/WrappedList.dart
diff --git a/tools/dom/src/WrappedList.dart b/tools/dom/src/WrappedList.dart
index 3f25f384c67b10d7dac320917c7c00eab0481ab6..2098e2fd27e825241fd000f4ce1882eb0112c579 100644
--- a/tools/dom/src/WrappedList.dart
+++ b/tools/dom/src/WrappedList.dart
@@ -80,10 +80,6 @@ class _WrappedList<E> implements List<E> {
 
   void remove(Object element) { _list.remove(element); }
 
-  void removeAll(Iterable elements) { _list.removeAll(elements); }
-
-  void retainAll(Iterable elements) { _list.retainAll(elements); }
-
   void removeWhere(bool test(E element)) { _list.removeWhere(test); }
 
   void retainWhere(bool test(E element)) { _list.retainWhere(test); }