Cleanup unused fgas/ code.

xfa/fgas/localization/fgas_localemgr.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_FGAS_LOCALIZATION_FGAS_LOCALEMGR_H_
-#define XFA_FGAS_LOCALIZATION_FGAS_LOCALEMGR_H_
-
-#include "xfa/fgas/localization/fgas_locale.h"
-
-class CFX_LocaleMgr : public IFX_LocaleMgr {
- public:
-  CFX_LocaleMgr(uint16_t wDefLCID);
-
-  void Release() override { delete this; }
-  uint16_t GetDefLocaleID() override;
-  IFX_Locale* GetDefLocale() override;
-  IFX_Locale* GetLocale(uint16_t lcid) override;
-  IFX_Locale* GetLocaleByName(const CFX_WideString& wsLocaleName) override;
-
-  CFX_MapPtrToPtr m_lcid2xml;
-
- protected:
-  ~CFX_LocaleMgr() override;
-  CFX_MapPtrToPtr m_lcid2locale;
-  uint16_t m_wDefLCID;
-};
-
-#endif  // XFA_FGAS_LOCALIZATION_FGAS_LOCALEMGR_H_