pdfium: Fix all -Wdelete-non-virtual-dtor violations on Mac.

core/src/fxcrt/extension.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 _FXCRT_EXTENSION_IMP_
 #define _FXCRT_EXTENSION_IMP_
 class IFXCRT_FileAccess
 {
 public:
     virtual ~IFXCRT_FileAccess() {}
     virtual FX_BOOL             Open(FX_BSTR fileName, FX_DWORD dwMode) = 0;
     virtual FX_BOOL             Open(FX_WSTR fileName, FX_DWORD dwMode) = 0;
     virtual void                Close() = 0;
     virtual void                Release() = 0;
     virtual FX_FILESIZE GetSize() const = 0;
     virtual FX_FILESIZE GetPosition() const = 0;
     virtual FX_FILESIZE SetPosition(FX_FILESIZE pos) = 0;
     virtual size_t              Read(void* pBuffer, size_t szBuffer) = 0;
     virtual size_t              Write(const void* pBuffer, size_t szBuffer) = 0;
     virtual size_t              ReadPos(void* pBuffer, size_t szBuffer, FX_FILESIZE pos) = 0;
     virtual size_t              WritePos(const void* pBuffer, size_t szBuffer, FX_FILESIZE pos) = 0;
     virtual FX_BOOL             Flush() = 0;
     virtual FX_BOOL             Truncate(FX_FILESIZE szFile) = 0;
 };
 IFXCRT_FileAccess*      FXCRT_FileAccess_Create();
-class CFX_CRTFileStream : public IFX_FileStream, public CFX_Object
+class CFX_CRTFileStream FX_FINAL : public IFX_FileStream, public CFX_Object
 {
 public:
     CFX_CRTFileStream(IFXCRT_FileAccess* pFA) : m_pFile(pFA), m_dwCount(1), m_bUseRange(FALSE), m_nOffset(0), m_nSize(0) {}
     ~CFX_CRTFileStream()
     {
         if (m_pFile) {
             m_pFile->Release();
         }
     }
     virtual IFX_FileStream*             Retain()
@@ skipping 71 matching lines @@
     }
     IFXCRT_FileAccess*  m_pFile;
     FX_DWORD                    m_dwCount;
     FX_BOOL                             m_bUseRange;
     FX_FILESIZE                 m_nOffset;
     FX_FILESIZE                 m_nSize;
 };
 #define FX_MEMSTREAM_BlockSize          (64 * 1024)
 #define FX_MEMSTREAM_Consecutive        0x01
 #define FX_MEMSTREAM_TakeOver           0x02
-class CFX_MemoryStream : public IFX_MemoryStream, public CFX_Object
+class CFX_MemoryStream FX_FINAL : public IFX_MemoryStream, public CFX_Object
 {
 public:
     CFX_MemoryStream(FX_BOOL bConsecutive)
         : m_dwCount(1)
         , m_nTotalSize(0)
         , m_nCurSize(0)
         , m_nCurPos(0)
         , m_nGrowSize(FX_MEMSTREAM_BlockSize)
         , m_bUseRange(FALSE)
     {
@@ skipping 258 matching lines @@
     FX_DWORD mt[MT_N];
 } FX_MTRANDOMCONTEXT, * FX_LPMTRANDOMCONTEXT;
 typedef FX_MTRANDOMCONTEXT const * FX_LPCMTRANDOMCONTEXT;
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 FX_BOOL FX_GenerateCryptoRandom(FX_LPDWORD pBuffer, FX_INT32 iCount);
 #endif
 #ifdef __cplusplus
 }
 #endif
 #endif