Do not do unnecessary recursive deletes for files.

chrome/installer/util/copy_tree_work_item_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/files/file_util.h"
@@ skipping 542 matching lines @@
 
   // verify that the source, destination have not changed and backup path
   // does not exist after rollback also
   EXPECT_TRUE(base::PathExists(file_name_from));
   EXPECT_TRUE(base::PathExists(file_name_to));
   EXPECT_EQ(0, ReadTextFile(file_name_from.value()).compare(text_content_1));
   EXPECT_TRUE(base::ContentsEqual(exe_full_path, file_name_to));
   EXPECT_FALSE(base::PathExists(backup_file));
 
   // Now delete the destination and try copying the file again.
-  base::DeleteFile(file_name_to, true);
+  base::DeleteFile(file_name_to, false);
   work_item.reset(WorkItem::CreateCopyTreeWorkItem(
       file_name_from, file_name_to,
       temp_dir_.path(), WorkItem::IF_NOT_PRESENT,
       base::FilePath()));
   EXPECT_TRUE(work_item->Do());
 
   // verify that the source, destination are the same and backup path
   // does not exist
   EXPECT_TRUE(base::PathExists(file_name_from));
   EXPECT_TRUE(base::PathExists(file_name_to));
@@ skipping 138 matching lines @@
   EXPECT_TRUE(base::ContentsEqual(file_name_from_1, file_name_to_1));
 
   base::FilePath file_name_to_2(dir_name_to);
   file_name_to_2 = file_name_to_2.AppendASCII("2");
   file_name_to_2 = file_name_to_2.AppendASCII("File_2.txt");
   EXPECT_TRUE(base::PathExists(file_name_to_2));
   VLOG(1) << "compare " << file_name_from_2.value()
           << " and " << file_name_to_2.value();
   EXPECT_TRUE(base::ContentsEqual(file_name_from_2, file_name_to_2));
 }