Move FileEnumerator to its own file, do some refactoring.

chrome/installer/test/alternate_version_generator.cc

Index: chrome/installer/test/alternate_version_generator.cc
diff --git a/chrome/installer/test/alternate_version_generator.cc b/chrome/installer/test/alternate_version_generator.cc
index 7811be4455d15b90ff6f8c704c8b9094f0637d4c..8222ba929a86d2a6e6478fed0d0fea497aaa6018 100644
--- a/chrome/installer/test/alternate_version_generator.cc
+++ b/chrome/installer/test/alternate_version_generator.cc
@@ -34,6 +34,7 @@
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
@@ -432,8 +433,7 @@ bool ApplyAlternateVersion(const base::FilePath& work_dir,
 
   // Modify all .dll and .exe files with the current version.
   bool doing_great = true;
-  file_util::FileEnumerator all_files(work_dir, true,
-                                      file_util::FileEnumerator::FILES);
+  base::FileEnumerator all_files(work_dir, true, base::FileEnumerator::FILES);
   do {
     base::FilePath file = all_files.Next();
     if (file.empty()) {