sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index cdf75cf3ffad12a77228faed8090154e3837b39c..cbb9e0d0698a421dce6d688e2a352e19d0421700 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -8917,6 +8917,10 @@ class _ChildrenElementList implements List {
   Iterator<Element> get iterator => toList().iterator;
 
   void addAll(Iterable<Element> iterable) {
+    if (iterable is _ChildNodeListLazy) {
+      iterable = new List.from(iterable);
+    }
+
     for (Element element in iterable) {
       _element.$dom_appendChild(element);
     }
@@ -18567,6 +18571,9 @@ class _ChildNodeListLazy implements List {
 
 
   void addAll(Iterable<Node> iterable) {
+    if (iterable is _ChildNodeListLazy) {
+      iterable = new List.from(iterable);
+    }
     for (Node node in iterable) {
       _this.$dom_appendChild(node);
     }