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

ui/shell_dialogs/selected_file_info.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 "ui/shell_dialogs/selected_file_info.h"
 
 namespace ui {
 
 SelectedFileInfo::SelectedFileInfo() {}
 
 SelectedFileInfo::SelectedFileInfo(const base::FilePath& in_file_path,
                                    const base::FilePath& in_local_path)
     : file_path(in_file_path),
       local_path(in_local_path) {
-  display_name = in_file_path.BaseName().value();
+  SetHideFileExtension(false);
 }
 
 SelectedFileInfo::~SelectedFileInfo() {}
 
+void SelectedFileInfo::SetHideFileExtension(bool hide_extension) {
+  hide_file_extension = hide_extension;
+  if (hide_file_extension) {
+    display_name = file_path.BaseName().RemoveExtension().value();
+  } else {
+    display_name = file_path.BaseName().value();
+  }
+}
+
 }  // namespace ui