Make AddIndirectObject() take a unique_ptr.

core/fpdfapi/parser/cpdf_indirect_object_holder.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_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_
 #define CORE_FPDFAPI_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_
 
 #include <map>
 #include <memory>
 
 #include "core/fxcrt/fx_system.h"
+#include "third_party/base/ptr_util.h"
 
 class CPDF_Object;
 
 class CPDF_IndirectObjectHolder {
  public:
   using const_iterator =
       std::map<uint32_t, std::unique_ptr<CPDF_Object>>::const_iterator;
 
   CPDF_IndirectObjectHolder();
   virtual ~CPDF_IndirectObjectHolder();
 
   CPDF_Object* GetIndirectObject(uint32_t objnum) const;
   CPDF_Object* GetOrParseIndirectObject(uint32_t objnum);
   void DeleteIndirectObject(uint32_t objnum);
 
-  // Take ownership of |pObj|.
-  uint32_t AddIndirectObject(CPDF_Object* pObj);
+  // Creates and adds a new object owned by the indirect object holder,
+  // and returns an unowned pointer to it.
+  template <typename T, typename... Args>
+  T* NewIndirect(Args... args) {
+    return static_cast<T*>(AddIndirectObject(pdfium::MakeUnique<T>(args...)));
+  }
+
+  // Takes ownership of |pObj|, returns unowned pointer to it.
+  CPDF_Object* AddIndirectObject(std::unique_ptr<CPDF_Object> pObj);
+
+  // Always takes ownership of |pObj|, return true if higher generation number.
   bool ReplaceIndirectObjectIfHigherGeneration(
       uint32_t objnum,
       std::unique_ptr<CPDF_Object> pObj);
 
   uint32_t GetLastObjNum() const { return m_LastObjNum; }
   void SetLastObjNum(uint32_t objnum) { m_LastObjNum = objnum; }
 
   const_iterator begin() const { return m_IndirectObjs.begin(); }
   const_iterator end() const { return m_IndirectObjs.end(); }
 
  protected:
   virtual std::unique_ptr<CPDF_Object> ParseIndirectObject(uint32_t objnum);
 
  private:
   uint32_t m_LastObjNum;
   std::map<uint32_t, std::unique_ptr<CPDF_Object>> m_IndirectObjs;
 };
 
 #endif  // CORE_FPDFAPI_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_