Enable "Hide Extension" option when "Save Link As" on the Mac

ui/shell_dialogs/selected_file_info.h

 // Copyright (c) 2013 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 UI_SHELL_DIALOGS_SELECTED_FILE_INFO_H_
 #define UI_SHELL_DIALOGS_SELECTED_FILE_INFO_H_
 
 #include <vector>
 
 #include "base/files/file_path.h"
@@ skipping 13 matching lines @@
   // /drive_cache/temporary/d41d8cd98f00b204e9800998ecf8427e vs.
   // /special/drive/foo.txt).
   base::FilePath local_path;
 
   // This field is optional. The display name contains only the base name
   // portion of a file name (ex. no path separators), and used for displaying
   // selected file names. If this field is empty, the base name portion of
   // |path| is used for displaying.
   base::FilePath::StringType display_name;
 
+  // On the Mac, a user can set a selected file to hide its file extension when
+  // listed in the Finder.
+  bool hide_file_extension;
+
   SelectedFileInfo();
   SelectedFileInfo(const base::FilePath& in_file_path,
                    const base::FilePath& in_local_path);
   ~SelectedFileInfo();
+
+  // Records that this FilePath represents a file that should hide its
+  // file extension and adjusts |display_name| accordingly.
+  void SetHideFileExtension(bool hide_extension);
 };
 
 }  // namespace ui
 
 #endif  // UI_SHELL_DIALOGS_SELECTED_FILE_INFO_H_