Move xfa/include/fwl/{theme,lightwidget} to xfa/fwl

xfa/include/fwl/lightwidget/app.h

-// Copyright 2014 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#ifndef XFA_INCLUDE_FWL_LIGHTWIDGET_APP_H_
-#define XFA_INCLUDE_FWL_LIGHTWIDGET_APP_H_
-
-#include "xfa/fwl/core/fwl_error.h"
-
-class CFWL_Theme;
-class IFWL_App;
-
-class CFWL_App {
- public:
-  CFWL_App();
-  virtual ~CFWL_App();
-
-  FWL_ERR Initialize();
-  FWL_ERR Exit(int32_t iExitCode);
-
-  CFWL_Theme* GetTheme() const { return m_pTheme; }
-  IFWL_App* GetInterface() const { return m_pIface; }
-
- private:
-  IFWL_App* m_pIface;
-  CFWL_Theme* m_pTheme;
-};
-
-#endif  // XFA_INCLUDE_FWL_LIGHTWIDGET_APP_H_