Use a direct include of strings headers in ui/, part 2.

ui/shell_dialogs/select_file_dialog.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_SELECT_FILE_DIALOG_H_
 #define UI_SHELL_DIALOGS_SELECT_FILE_DIALOG_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/shell_dialogs/base_shell_dialog.h"
 #include "ui/shell_dialogs/shell_dialogs_export.h"
 
 namespace ui {
 class SelectFileDialogFactory;
 class SelectFilePolicy;
 struct SelectedFileInfo;
 class ShellDialogsDelegate;
 
@@ skipping 171 matching lines @@
   virtual bool HasMultipleFileTypeChoicesImpl() = 0;
 
   scoped_ptr<SelectFilePolicy> select_file_policy_;
 
   DISALLOW_COPY_AND_ASSIGN(SelectFileDialog);
 };
 
 }  // namespace ui
 
 #endif  // UI_SHELL_DIALOGS_SELECT_FILE_DIALOG_H_