Add synchronous directory listing to dart:io Directory.

sdk/lib/io/directory.dart

Index: sdk/lib/io/directory.dart
diff --git a/sdk/lib/io/directory.dart b/sdk/lib/io/directory.dart
index 42411ac712801b1d398e37009488cf69667dab92..60717b86e7192028c459c3dc31b551352d4a6133 100644
--- a/sdk/lib/io/directory.dart
+++ b/sdk/lib/io/directory.dart
@@ -140,6 +140,13 @@ abstract class Directory {
   DirectoryLister list({bool recursive: false});
 
   /**
+   * List the sub-directories and files of this
+   * [Directory]. Optionally recurse into sub-directories. Returns a
+   * List containing Directory and File objects.
+   */
+  List listSync({bool recursive: false});
+
+  /**
    * Returns a human readable string for this Directory instance.
    */
   String toString();