Fixing analyzer issues in DOM libs.

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

Index: tools/dom/templates/html/impl/impl_Element.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_Element.darttemplate b/tools/dom/templates/html/impl/impl_Element.darttemplate
index 52c772168224c5d8b44187f5248994985efc118b..c3288ae05f7265c3289db3fe6a62d28b08e490f9 100644
--- a/tools/dom/templates/html/impl/impl_Element.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Element.darttemplate
@@ -137,6 +137,9 @@ class _ChildrenElementList implements List {
     }
   }
 
+  List<Element> get reversed =>
+      new ReversedListView<Element>(this, 0, null);
+
   void sort([int compare(Element a, Element b)]) {
     throw new UnsupportedError('TODO(jacobr): should we impl?');
   }
@@ -160,19 +163,19 @@ class _ChildrenElementList implements List {
   }
 
   void removeAll(Iterable elements) {
-    Collections.removeAll(this, elements);
+    IterableMixinWorkaround.removeAll(this, elements);
   }
 
   void retainAll(Iterable elements) {
-    Collections.retainAll(this, elements);
+    IterableMixinWorkaround.retainAll(this, elements);
   }
 
   void removeMatching(bool test(Element element)) {
-    Collections.removeMatching(this, test);
+    IterableMixinWorkaround.removeMatching(this, test);
   }
 
   void retainMatching(bool test(Element element)) {
-    Collections.retainMatching(this, test);
+    IterableMixinWorkaround.retainMatching(this, test);
   }
 
   void removeRange(int start, int rangeLength) {
@@ -359,6 +362,9 @@ class _FrozenElementList implements List {
     throw new UnsupportedError('');
   }
 
+  List<Element> get reversed =>
+      new ReversedListView<Element>(this, 0, null);
+
   void sort([int compare(Element a, Element b)]) {
     throw new UnsupportedError('');
   }