windows: Fix a few things clang complains about.

base/file_util_win.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 "base/file_util.h"
 
 #include <windows.h>
 #include <propvarutil.h>
 #include <psapi.h>
 #include <shellapi.h>
@@ skipping 970 matching lines @@
     ::CloseHandle(file_);
 
   data_ = NULL;
   file_mapping_ = file_ = INVALID_HANDLE_VALUE;
   length_ = INVALID_FILE_SIZE;
 }
 
 bool HasFileBeenModifiedSince(const FileEnumerator::FindInfo& find_info,
                               const base::Time& cutoff_time) {
   base::ThreadRestrictions::AssertIOAllowed();
+  FILETIME file_time = cutoff_time.ToFileTime();
   long result = CompareFileTime(&find_info.ftLastWriteTime,  // NOLINT
-                                &cutoff_time.ToFileTime());
+                                &file_time);
   return result == 1 || result == 0;
 }
 
 bool NormalizeFilePath(const FilePath& path, FilePath* real_path) {
   base::ThreadRestrictions::AssertIOAllowed();
   FilePath mapped_file;
   if (!NormalizeToNativeFilePath(path, &mapped_file))
     return false;
   // NormalizeToNativeFilePath() will return a path that starts with
   // "\Device\Harddisk...".  Helper DevicePathToDriveLetterPath()
@@ skipping 161 matching lines @@
       uint8 unused = *(touch + offset);
       offset += step_size;
     }
     FreeLibrary(dll_module);
   }
 
   return true;
 }
 
 }  // namespace file_util