Add synchronous directory listing to dart:io Directory.

tests/standalone/io/directory_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Directory listing test.
 
 import "dart:io";
 import "dart:isolate";
 
 class DirectoryTest {
   static void testListing() {
     bool listedDir = false;
     bool listedFile = false;
 
     Directory directory = new Directory("").createTempSync();
     Directory subDirectory = new Directory("${directory.path}/subdir");
     Expect.isTrue('$directory'.contains(directory.path));
     Expect.isFalse(subDirectory.existsSync());
     subDirectory.createSync();
     Expect.isTrue(subDirectory.existsSync());
     File f = new File('${subDirectory.path}/file.txt');
     Expect.isFalse(f.existsSync());
     f.createSync();
 
+    void testSyncListing(bool recursive) {
+      for (var entry in directory.listSync(recursive: recursive)) {
+        if (entry is File) {
+          Expect.isTrue(entry.name.contains(directory.path));
+          Expect.isTrue(entry.name.contains('subdir'));
+          Expect.isTrue(entry.name.contains('file.txt'));
+          Expect.isFalse(listedFile);
+          listedFile = true;
+        } else {
+          Expect.isTrue(entry is Directory);
+          Expect.isTrue(entry.path.contains(directory.path));
+          Expect.isTrue(entry.path.contains('subdir'));
+          Expect.isFalse(listedDir);
+          listedDir = true;
+        }
+      }
+      Expect.equals(listedFile, recursive);
+      Expect.isTrue(listedDir);
+      listedFile = false;
+      listedDir = false;
+    }
+
+    testSyncListing(true);
+    testSyncListing(false);
+
     var lister = directory.list(recursive: true);
 
     lister.onDir = (dir) {
       listedDir = true;
       Expect.isTrue(dir.contains(directory.path));
       Expect.isTrue(dir.contains('subdir'));
     };
 
     lister.onFile = (f) {
       listedFile = true;
@@ skipping 554 matching lines @@
   testCreateTempErrorSync();
   testCreateTempError();
   testCreateExistingSync();
   testCreateExisting();
   testCreateDirExistingFileSync();
   testCreateDirExistingFile();
   testCreateRecursive();
   testCreateRecursiveSync();
   testRename();
 }