Dynamic -> dynamic.

sdk/lib/core/set.dart

Index: sdk/lib/core/set.dart
diff --git a/sdk/lib/core/set.dart b/sdk/lib/core/set.dart
index c4bacbfa0a515cca3fe7f6ca3ef997062fbb76fe..47c706f287efd9b7f6f9c2789c553932bfc6a9de 100644
--- a/sdk/lib/core/set.dart
+++ b/sdk/lib/core/set.dart
@@ -153,8 +153,8 @@ class _HashSetImpl<E> implements HashSet<E> {
     return result;
   }
 
-  Dynamic reduce(Dynamic initialValue,
-                 Dynamic combine(Dynamic previousValue, E element)) {
+  dynamic reduce(dynamic initialValue,
+                 dynamic combine(dynamic previousValue, E element)) {
     return Collections.reduce(this, initialValue, combine);
   }