Move FileEnumerator to its own file, do some refactoring.

chrome/installer/util/installer_state_unittest.cc

 // Copyright (c) 2012 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 <windows.h>
 
 #include <fstream>
 
 #include "base/base_paths.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/files/scoped_temp_dir.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_util.h"
 #include "base/test/test_reg_util_win.h"
 #include "base/utf_string_conversions.h"
 #include "base/version.h"
 #include "base/win/registry.h"
 #include "base/win/scoped_handle.h"
@@ skipping 555 matching lines @@
 
   // What we expect to have left.
   std::set<std::string> expected_remaining_dirs;
   expected_remaining_dirs.insert(kOldVersion);
   expected_remaining_dirs.insert(kNewVersion);
   expected_remaining_dirs.insert(kOldChromeExeVersion);
   expected_remaining_dirs.insert(kChromeExeVersion);
   expected_remaining_dirs.insert(kNewChromeExeVersion);
 
   // Enumerate dirs in target_path(), ensure only desired remain.
-  file_util::FileEnumerator version_enum(installer_state.target_path(), false,
-      file_util::FileEnumerator::DIRECTORIES);
+  base::FileEnumerator version_enum(installer_state.target_path(), false,
+                                    base::FileEnumerator::DIRECTORIES);
   for (base::FilePath next_version = version_enum.Next(); !next_version.empty();
        next_version = version_enum.Next()) {
     base::FilePath dir_name(next_version.BaseName());
     Version version(WideToASCII(dir_name.value()));
     if (version.IsValid()) {
       EXPECT_TRUE(expected_remaining_dirs.erase(version.GetString()))
           << "Unexpected version dir found: " << version.GetString();
     }
   }
 
@@ skipping 149 matching lines @@
   // Critical update newer than the new version.
   EXPECT_FALSE(
       installer_state.DetermineCriticalVersion(NULL, *pv_version_).IsValid());
   EXPECT_FALSE(
       installer_state.DetermineCriticalVersion(opv_version_, *pv_version_)
           .IsValid());
   EXPECT_FALSE(
       installer_state.DetermineCriticalVersion(pv_version_, *pv_version_)
           .IsValid());
 }