Big merge from experimental to bleeding edge.

utils/pub/validator/directory.dart

Index: utils/pub/validator/directory.dart
diff --git a/utils/pub/validator/directory.dart b/utils/pub/validator/directory.dart
index 07ad933ce56b2ee4af3e2826ced8fa78854e094d..80568bab2e8f477ea63a7aa68ff4c56875a7df2a 100644
--- a/utils/pub/validator/directory.dart
+++ b/utils/pub/validator/directory.dart
@@ -17,8 +17,8 @@ class DirectoryValidator extends Validator {
 
   Future validate() {
     return listDir(entrypoint.root.dir).chain((dirs) {
-      return Futures.wait(dirs.map((dir) {
-        return dirExists(dir).transform((exists) {
+      return Futures.wait(dirs.mappedBy((dir) {
+        return dirExists(dir).then((exists) {
           if (!exists) return;
 
           dir = basename(dir);