Use iterator, moveNext(), current.

pkg/http/lib/src/utils.dart

Index: pkg/http/lib/src/utils.dart
diff --git a/pkg/http/lib/src/utils.dart b/pkg/http/lib/src/utils.dart
index 29d8f034c50d116793156e6fb8849b160af7d4f3..f3eece87976d63ded7a89704eee94ae91d207940 100644
--- a/pkg/http/lib/src/utils.dart
+++ b/pkg/http/lib/src/utils.dart
@@ -176,10 +176,10 @@ Future get async {
 /// The return values of all [Future]s are discarded. Any errors will cause the
 /// iteration to stop and will be piped through the return value.
 Future forEachFuture(Iterable input, Future fn(element)) {
-  var iterator = input.iterator();
+  var iterator = input.iterator;
   Future nextElement(_) {
-    if (!iterator.hasNext) return new Future.immediate(null);
-    return fn(iterator.next()).chain(nextElement);
+    if (!iterator.moveNext()) return new Future.immediate(null);
+    return fn(iterator.current).chain(nextElement);
   }
   return nextElement(null);
 }