Merge to XFA: Use override in more classes in fpdfsdk/

fpdfsdk/src/fpdfsave.cpp

Index: fpdfsdk/src/fpdfsave.cpp
diff --git a/fpdfsdk/src/fpdfsave.cpp b/fpdfsdk/src/fpdfsave.cpp
index f56cc442f0ae162674e77a34bc7914fdeb5dd2f1..7a666bceb865055ae2b2c4f574e74023cf277e87 100644
--- a/fpdfsdk/src/fpdfsave.cpp
+++ b/fpdfsdk/src/fpdfsave.cpp
@@ -22,10 +22,12 @@ class CFX_IFileWrite final : public IFX_StreamWrite {
  public:
   CFX_IFileWrite();
   FX_BOOL Init(FPDF_FILEWRITE* pFileWriteStruct);
-  virtual FX_BOOL WriteBlock(const void* pData, size_t size) override;
-  virtual void Release() override {}
+  FX_BOOL WriteBlock(const void* pData, size_t size) override;
+  void Release() override;
 
  protected:
+  ~CFX_IFileWrite() override {}
+
   FPDF_FILEWRITE* m_pFileWriteStruct;
 };
 
@@ -49,6 +51,10 @@ FX_BOOL CFX_IFileWrite::WriteBlock(const void* pData, size_t size) {
   return TRUE;
 }
 
+void CFX_IFileWrite::Release() {
+  delete this;
+}
+
 #define XFA_DATASETS 0
 #define XFA_FORMS 1
 
@@ -311,7 +317,6 @@ FPDF_BOOL _FPDF_Doc_Save(FPDF_DOCUMENT document,
   bRet = FileMaker.Create(pStreamWrite, flags);
 
   _SendPostSaveToXFADoc(pDoc);
-  // pDoc->_ClearChangeMark();
 
   for (int i = 0; i < fileList.GetSize(); i++) {
     IFX_FileStream* pFile = (IFX_FileStream*)fileList.GetAt(i);
@@ -319,7 +324,7 @@ FPDF_BOOL _FPDF_Doc_Save(FPDF_DOCUMENT document,
   }
   fileList.RemoveAll();
 
-  delete pStreamWrite;
+  pStreamWrite->Release();
   return bRet;
 }