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

ui/shell_dialogs/selected_file_info.h

Index: ui/shell_dialogs/selected_file_info.h
diff --git a/ui/shell_dialogs/selected_file_info.h b/ui/shell_dialogs/selected_file_info.h
index a1789c970384dcc5340a151c45faa283bd80b2fb..004b3b5f43d9b184d0181ddefd1209d6ddcaea84 100644
--- a/ui/shell_dialogs/selected_file_info.h
+++ b/ui/shell_dialogs/selected_file_info.h
@@ -31,10 +31,18 @@ struct SHELL_DIALOGS_EXPORT SelectedFileInfo {
   // |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