Cleanup forward declarations.

xfa/include/fwl/theme/widgettp.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_THEME_WIDGETTP_H_
 #define XFA_INCLUDE_FWL_THEME_WIDGETTP_H_
 
 #include <memory>
 #include <vector>
 
 #include "core/include/fxcrt/fx_coordinates.h"
 #include "core/include/fxcrt/fx_system.h"
 #include "xfa/include/fwl/core/fwl_error.h"
 #include "xfa/include/fwl/core/fwl_theme.h"
 #include "xfa/include/fwl/core/fwl_widget.h"
 #include "xfa/include/fwl/theme/utils.h"
 
-class IFWL_ThemeProvider;
 class IFWL_Widget;
 class IFDE_TextOut;
 class IFX_Font;
 class IFX_FontMgr;
 class CFWL_ArrowData;
 
 #if _FXM_PLATFORM_ != _FXM_PLATFORM_WINDOWS_
 class IFX_FontSourceEnum;
 #endif
 
@@ skipping 179 matching lines @@
 
  protected:
   CFWL_FontManager();
   virtual ~CFWL_FontManager();
 
   static CFWL_FontManager* s_FontManager;
   std::vector<std::unique_ptr<CFWL_FontData>> m_FontsArray;
 };
 
 #endif  // XFA_INCLUDE_FWL_THEME_WIDGETTP_H_