Catch stray Retains() and Releases() outside of RetainPtr<>.

xfa/fxfa/parser/cxfa_widetextread.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 XFA_FXFA_PARSER_CXFA_WIDETEXTREAD_H_
 #define XFA_FXFA_PARSER_CXFA_WIDETEXTREAD_H_
 
+#include "core/fxcrt/cfx_retain_ptr.h"
 #include "xfa/fgas/crt/fgas_stream.h"
 
 class CXFA_WideTextRead : public IFGAS_Stream {
  public:
-  explicit CXFA_WideTextRead(const CFX_WideString& wsBuffer);
+  template <typename T, typename... Args>
+  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
   // IFGAS_Stream
   uint32_t GetAccessModes() const override;
   int32_t GetLength() const override;
   int32_t Seek(FX_STREAMSEEK eSeek, int32_t iOffset) override;
   int32_t GetPosition() override;
   bool IsEOF() const override;
   int32_t ReadData(uint8_t* pBuffer, int32_t iBufferSize) override;
   int32_t ReadString(FX_WCHAR* pStr, int32_t iMaxLength, bool& bEOS) override;
   int32_t WriteData(const uint8_t* pBuffer, int32_t iBufferSize) override;
   int32_t WriteString(const FX_WCHAR* pStr, int32_t iLength) override;
   void Flush() override {}
   bool SetLength(int32_t iLength) override;
   int32_t GetBOM(uint8_t bom[4]) const override;
   uint16_t GetCodePage() const override;
   uint16_t SetCodePage(uint16_t wCodePage) override;
   CFX_RetainPtr<IFGAS_Stream> CreateSharedStream(uint32_t dwAccess,
                                                  int32_t iOffset,
                                                  int32_t iLength) override;
 
   CFX_WideString GetSrcText() const;
 
  protected:
+  explicit CXFA_WideTextRead(const CFX_WideString& wsBuffer);
+  ~CXFA_WideTextRead() override;
+
   CFX_WideString m_wsBuffer;
   int32_t m_iPosition;
 };
 
 #endif  // XFA_FXFA_PARSER_CXFA_WIDETEXTREAD_H_