Move FileEnumerator to its own file, do some refactoring.

chrome/common/extensions/extension_l10n_util.cc

Index: chrome/common/extensions/extension_l10n_util.cc
diff --git a/chrome/common/extensions/extension_l10n_util.cc b/chrome/common/extensions/extension_l10n_util.cc
index bc56dffd645b4e8202ea4c630451dc6a56ce42f4..7949353f827add3209593fd7026dd884a8b3ca35 100644
--- a/chrome/common/extensions/extension_l10n_util.cc
+++ b/chrome/common/extensions/extension_l10n_util.cc
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/logging.h"
 #include "base/memory/linked_ptr.h"
@@ -258,9 +259,9 @@ bool GetValidLocales(const base::FilePath& locale_path,
   GetAllLocales(&chrome_locales);
 
   // Enumerate all supplied locales in the extension.
-  file_util::FileEnumerator locales(locale_path,
-                                    false,
-                                    file_util::FileEnumerator::DIRECTORIES);
+  base::FileEnumerator locales(locale_path,
+                               false,
+                               base::FileEnumerator::DIRECTORIES);
   base::FilePath locale_folder;
   while (!(locale_folder = locales.Next()).empty()) {
     std::string locale_name = locale_folder.BaseName().MaybeAsASCII();