Take advantage of some newer optimizations of FindFirstFile.

base/files/file_enumerator.h

 // 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.
 
 #ifndef BASE_FILES_FILE_ENUMERATOR_H_
 #define BASE_FILES_FILE_ENUMERATOR_H_
 
 #include <stack>
 #include <vector>
 
@@ skipping 35 matching lines @@
 
     // The name of the file. This will not include any path information. This
     // is in constrast to the value returned by FileEnumerator.Next() which
     // includes the |root_path| passed into the FileEnumerator constructor.
     FilePath GetName() const;
 
     int64 GetSize() const;
     Time GetLastModifiedTime() const;
 
 #if defined(OS_WIN)
+    // Note that the cAlternateFileName (used to hold the "short" 8.3 name)
+    // of the WIN32_FIND_DATA will be empty. Since we don't use short file
+    // names, we tell Windows to omit it which speeds up the query slightly.
     const WIN32_FIND_DATA& find_data() const { return find_data_; }
 #elif defined(OS_POSIX)
     const struct stat& stat() const { return stat_; }
 #endif
 
    private:
     friend class FileEnumerator;
 
 #if defined(OS_WIN)
     WIN32_FIND_DATA find_data_;
@@ skipping 81 matching lines @@
   // A stack that keeps track of which subdirectories we still need to
   // enumerate in the breadth-first search.
   std::stack<FilePath> pending_paths_;
 
   DISALLOW_COPY_AND_ASSIGN(FileEnumerator);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_ENUMERATOR_H_