Use more unique_ptrs in CPDF_Image.

core/fpdfapi/page/cpdf_textobject.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_PAGE_CPDF_TEXTOBJECT_H_
 #define CORE_FPDFAPI_PAGE_CPDF_TEXTOBJECT_H_
 
+#include <memory>
+
 #include "core/fpdfapi/page/cpdf_pageobject.h"
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 
 struct CPDF_TextObjectItem {
   uint32_t m_CharCode;
   FX_FLOAT m_OriginX;
   FX_FLOAT m_OriginY;
 };
 
 class CPDF_TextObject : public CPDF_PageObject {
  public:
   CPDF_TextObject();
   ~CPDF_TextObject() override;
 
   // CPDF_PageObject
-  CPDF_TextObject* Clone() const override;
   Type GetType() const override;
   void Transform(const CFX_Matrix& matrix) override;
   bool IsText() const override;
   CPDF_TextObject* AsText() override;
   const CPDF_TextObject* AsText() const override;
 
+  std::unique_ptr<CPDF_TextObject> Clone() const;
   int CountItems() const;
   void GetItemInfo(int index, CPDF_TextObjectItem* pInfo) const;
   int CountChars() const;
   void GetCharInfo(int index, uint32_t& charcode, FX_FLOAT& kerning) const;
   void GetCharInfo(int index, CPDF_TextObjectItem* pInfo) const;
   FX_FLOAT GetCharWidth(uint32_t charcode) const;
   FX_FLOAT GetPosX() const;
   FX_FLOAT GetPosY() const;
   void GetTextMatrix(CFX_Matrix* pMatrix) const;
   CPDF_Font* GetFont() const;
@@ skipping 16 matching lines @@
                         FX_FLOAT horz_scale);
 
   FX_FLOAT m_PosX;
   FX_FLOAT m_PosY;
   int m_nChars;
   uint32_t* m_pCharCodes;
   FX_FLOAT* m_pCharPos;
 };
 
 #endif  // CORE_FPDFAPI_PAGE_CPDF_TEXTOBJECT_H_