Remove CFX_PrivateData from CPDF_Page

fpdfsdk/include/fsdk_rendercontext.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 FPDFSDK_INCLUDE_FSDK_RENDERCONTEXT_H_
 #define FPDFSDK_INCLUDE_FSDK_RENDERCONTEXT_H_
 
 #include "core/fpdfapi/fpdf_render/include/cpdf_progressiverenderer.h"
+#include "core/fxcrt/include/fx_basic.h"
 #include "fpdfsdk/include/fsdk_define.h"
 #include "public/fpdf_progressive.h"
 
 // Everything about rendering is put here: for OOM recovery
-class CRenderContext {
+class CRenderContext : public CFX_Deletable {
  public:
   CRenderContext() { Clear(); }
-  ~CRenderContext();
+  ~CRenderContext() override;
 
   void Clear();
 
   CFX_RenderDevice* m_pDevice;
   CPDF_RenderContext* m_pContext;
   CPDF_ProgressiveRenderer* m_pRenderer;
   CPDF_AnnotList* m_pAnnots;
   CPDF_RenderOptions* m_pOptions;
 #ifdef _WIN32_WCE
   CFX_DIBitmap* m_pBitmap;
   HBITMAP m_hBitmap;
 #endif
 };
 
 class IFSDK_PAUSE_Adapter : public IFX_Pause {
  public:
   explicit IFSDK_PAUSE_Adapter(IFSDK_PAUSE* IPause);
   ~IFSDK_PAUSE_Adapter() override;
 
   FX_BOOL NeedToPauseNow() override;
 
  private:
   IFSDK_PAUSE* m_IPause;
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_RENDERCONTEXT_H_