Move FileEnumerator to its own file, do some refactoring.

net/disk_cache/cache_util_posix.cc

 // Copyright (c) 2011 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.
 
 #include "net/disk_cache/cache_util.h"
 
 #include "base/file_util.h"
+#include "base/files/file_enumerator.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 
 namespace disk_cache {
 
 bool MoveCache(const base::FilePath& from_path, const base::FilePath& to_path) {
 #if defined(OS_CHROMEOS)
   // For ChromeOS, we don't actually want to rename the cache
   // directory, because if we do, then it'll get recreated through the
   // encrypted filesystem (with encrypted names), and we won't be able
   // to see these directories anymore in an unmounted encrypted
   // filesystem, so we just move each item in the cache to a new
   // directory.
   if (!file_util::CreateDirectory(to_path)) {
     LOG(ERROR) << "Unable to create destination cache directory.";
     return false;
   }
-  file_util::FileEnumerator iter(from_path, false /* not recursive */,
-      file_util::FileEnumerator::DIRECTORIES |
-      file_util::FileEnumerator::FILES);
+  base::FileEnumerator iter(from_path, false /* not recursive */,
+      base::FileEnumerator::DIRECTORIES | base::FileEnumerator::FILES);
   for (base::FilePath name = iter.Next(); !name.value().empty();
        name = iter.Next()) {
     base::FilePath destination = to_path.Append(name.BaseName());
     if (!file_util::Move(name, destination)) {
       LOG(ERROR) << "Unable to move cache item.";
       return false;
     }
   }
   return true;
 #else
   return file_util::Move(from_path, to_path);
 #endif
 }
 
 void DeleteCache(const base::FilePath& path, bool remove_folder) {
-  file_util::FileEnumerator iter(path,
-                                 /* recursive */ false,
-                                 file_util::FileEnumerator::FILES);
+  base::FileEnumerator iter(path,
+                            /* recursive */ false,
+                            base::FileEnumerator::FILES);
   for (base::FilePath file = iter.Next(); !file.value().empty();
        file = iter.Next()) {
     if (!file_util::Delete(file, /* recursive */ false)) {
       LOG(WARNING) << "Unable to delete cache.";
       return;
     }
   }
 
   if (remove_folder) {
     if (!file_util::Delete(path, /* recursive */ false)) {
       LOG(WARNING) << "Unable to delete cache folder.";
       return;
     }
   }
 }
 
 bool DeleteCacheFile(const base::FilePath& name) {
   return file_util::Delete(name, false);
 }
 
 }  // namespace disk_cache