Move ifx_renderdevicedriver to a separate file to share

core/fxge/include/fx_ge_win32.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 CORE_FXGE_INCLUDE_FX_GE_WIN32_H_
 #define CORE_FXGE_INCLUDE_FX_GE_WIN32_H_
 
 #ifdef _WIN32
 #ifndef _WINDOWS_
 #include <windows.h>
 #endif
 #define WINDIB_OPEN_MEMORY 0x1
 #define WINDIB_OPEN_PATHNAME 0x2
+
+class IFX_RenderDeviceDriver;
+
 typedef struct WINDIB_Open_Args_ {
   int flags;
 
   const uint8_t* memory_base;
 
   size_t memory_size;
 
   const FX_WCHAR* path_name;
 } WINDIB_Open_Args_;
 
@@ skipping 45 matching lines @@
  protected:
   HBITMAP m_hBitmap;
 
   HBITMAP m_hOldBitmap;
 
   HDC m_hDC;
 };
 #endif
 
 #endif  // CORE_FXGE_INCLUDE_FX_GE_WIN32_H_