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

tools/dom/templates/immutable_list_mixin.darttemplate

Index: tools/dom/templates/immutable_list_mixin.darttemplate
diff --git a/tools/dom/templates/immutable_list_mixin.darttemplate b/tools/dom/templates/immutable_list_mixin.darttemplate
index 5d1b5c5be4be2a3cd04069fd423682a3cbf77b5c..8b85dab6ee4ca931bb2f6545f06cee553dc811d1 100644
--- a/tools/dom/templates/immutable_list_mixin.darttemplate
+++ b/tools/dom/templates/immutable_list_mixin.darttemplate
@@ -155,14 +155,6 @@ $endif
     throw new UnsupportedError("Cannot remove from immutable List.");
   }
 
-  void removeAll(Iterable elements) {
-    throw new UnsupportedError("Cannot remove from immutable List.");
-  }
-
-  void retainAll(Iterable elements) {
-    throw new UnsupportedError("Cannot remove from immutable List.");
-  }
-
   void removeWhere(bool test($E element)) {
     throw new UnsupportedError("Cannot remove from immutable List.");
   }