Remove addLast from List.

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 a868eb0029d73f463c3165bff9f05a6bf61ea991..02f43e98ddaaef1c5f8f42149d3a57f0d74d1dc3 100644
--- a/tools/dom/templates/html/impl/impl_Element.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Element.darttemplate
@@ -137,8 +137,6 @@ class _ChildrenElementList implements List {
     return value;
   }
 
-  Element addLast(Element value) => add(value);
-
   Iterator<Element> get iterator => toList().iterator;
 
   void addAll(Iterable<Element> iterable) {
@@ -391,10 +389,6 @@ class _FrozenElementList implements List {
     throw new UnsupportedError('');
   }
 
-  void addLast(Element value) {
-    throw new UnsupportedError('');
-  }
-
   Iterator<Element> get iterator => new _FrozenElementListIterator(this);
 
   void addAll(Iterable<Element> iterable) {