Recommit changing List.skip/take/revert returns Iterable and remove mappedBy.

runtime/lib/byte_array.dart

Index: runtime/lib/byte_array.dart
diff --git a/runtime/lib/byte_array.dart b/runtime/lib/byte_array.dart
index 14b1b17fb351a3d9b8230bc0f7d49bf7a466d60d..7eb126a2afe49d35e8033bb4a054b18510e414cf 100644
--- a/runtime/lib/byte_array.dart
+++ b/runtime/lib/byte_array.dart
@@ -233,10 +233,6 @@ abstract class _ByteArrayBase {
     return IterableMixinWorkaround.mapList(this, f);
   }
 
-  List mappedBy(f(int element)) {
-    return IterableMixinWorkaround.mappedByList(this, f);
-  }
-
   String join([String separator]) {
     return IterableMixinWorkaround.join(this, separator);
   }