file_util: Convert the wstring version of IsDirectoryEmpty to FilePath.

base/file_util.cc

Index: base/file_util.cc
diff --git a/base/file_util.cc b/base/file_util.cc
index 5bc73cef08161eb9576dfad8aa73c2dad000196a..aea6e626b9b0bb8d8dbcb08068e76a240919ac58 100644
--- a/base/file_util.cc
+++ b/base/file_util.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -194,6 +194,15 @@ bool ReadFileToString(const FilePath& path, std::string* contents) {
   return true;
 }
 
+bool IsDirectoryEmpty(const FilePath& dir_path) {
+  FileEnumerator files(dir_path, false,
+      static_cast<FileEnumerator::FILE_TYPE>(
+          FileEnumerator::FILES | FileEnumerator::DIRECTORIES));
+  if (files.Next().value().empty())
+    return true;
+  return false;
+}
+
 FILE* CreateAndOpenTemporaryFile(FilePath* path) {
   FilePath directory;
   if (!GetTempDir(&directory))