Make code compile with clang_use_chrome_plugin (part I)

core/fpdfapi/fpdf_page/include/cpdf_pageobjectholder.h

 // Copyright 2016 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_FPDFAPI_FPDF_PAGE_INCLUDE_CPDF_PAGEOBJECTHOLDER_H_
 #define CORE_FPDFAPI_FPDF_PAGE_INCLUDE_CPDF_PAGEOBJECTHOLDER_H_
 
 #include "core/fpdfapi/fpdf_page/cpdf_pageobjectlist.h"
 #include "core/fxcrt/include/fx_coordinates.h"
 #include "core/fxcrt/include/fx_system.h"
 
 class IFX_Pause;
 class CPDF_Dictionary;
 class CPDF_Stream;
 class CPDF_Document;
 class CPDF_ContentParser;
 
 #define PDFTRANS_GROUP 0x0100
 #define PDFTRANS_ISOLATED 0x0200
 #define PDFTRANS_KNOCKOUT 0x0400
 
 class CPDF_PageObjectHolder {
  public:
   CPDF_PageObjectHolder();
+  virtual ~CPDF_PageObjectHolder();
 
   void ContinueParse(IFX_Pause* pPause);
   bool IsParsed() const { return m_ParseState == CONTENT_PARSED; }
 
   CPDF_PageObjectList* GetPageObjectList() { return &m_PageObjectList; }
   const CPDF_PageObjectList* GetPageObjectList() const {
     return &m_PageObjectList;
   }
 
   FX_BOOL BackgroundAlphaNeeded() const { return m_bBackgroundAlphaNeeded; }
@@ skipping 21 matching lines @@
   void LoadTransInfo();
 
   FX_BOOL m_bBackgroundAlphaNeeded;
   FX_BOOL m_bHasImageMask;
   ParseState m_ParseState;
   std::unique_ptr<CPDF_ContentParser> m_pParser;
   CPDF_PageObjectList m_PageObjectList;
 };
 
 #endif  // CORE_FPDFAPI_FPDF_PAGE_INCLUDE_CPDF_PAGEOBJECTHOLDER_H_