Add in a missing call to propagate the extension choices to the Save As dialog.

BUG=407972

Review URL: https://codereview.chromium.org/544123003

Cr-Commit-Position: refs/heads/master@{#293715}

chrome/utility/shell_handler_win.cc

@@ -64,6 +64,7 @@ void ShellHandler::OnGetSaveFileName(
   ui::win::OpenFileName open_file_name(params.owner, params.flags);
   open_file_name.SetInitialSelection(params.initial_directory,
                                      params.suggested_filename);
+  open_file_name.SetFilters(params.filters);
   open_file_name.GetOPENFILENAME()->nFilterIndex =
       params.one_based_filter_index;
   open_file_name.GetOPENFILENAME()->lpstrDefExt =