Refactor List.setRange function.

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 13eaa3080efd68f093803fcdd0f6117fe7b2eb30..a4872b370ce5ec3109e12c7761f95ace71cbb0f0 100644
--- a/tools/dom/templates/html/impl/impl_Element.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Element.darttemplate
@@ -166,8 +166,8 @@ class _ChildrenElementList extends ListBase<Element> {
     return _childElements.fold(initialValue, combine);
   }
 
-  void setRange(int start, int rangeLength, List from,
-                [int startFrom = 0]) {
+  void setRange(int start, int end, Iterable<Element> iterable,
+                [int skipCount = 0]) {
     throw new UnimplementedError();
   }
 
@@ -309,8 +309,8 @@ class _FrozenElementList extends ListBase {
     throw new UnsupportedError('');
   }
 
-  void setRange(int start, int rangeLength, List from,
-                [int startFrom = 0]) {
+  void setRange(int start, int end, Iterable<Element> iterable,
+                [int skipCount = 0]) {
     throw new UnsupportedError('');
   }