Make CPDF_Function::Load() return an unique_ptr.

core/fpdfapi/fpdf_page/fpdf_page_func.cpp

 // 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
 
 #include "core/fpdfapi/fpdf_page/pageint.h"
 
 #include <limits.h>
 
@@ skipping 774 matching lines @@
       break;
   }
   input = PDF_Interpolate(input, m_pBounds[i], m_pBounds[i + 1],
                           m_pEncode[i * 2], m_pEncode[i * 2 + 1]);
   int nresults;
   m_pSubFunctions[i]->Call(&input, kRequiredNumInputs, outputs, nresults);
   return TRUE;
 }
 
 // static
-CPDF_Function* CPDF_Function::Load(CPDF_Object* pFuncObj) {
+std::unique_ptr<CPDF_Function> CPDF_Function::Load(CPDF_Object* pFuncObj) {
+  std::unique_ptr<CPDF_Function> pFunc;
   if (!pFuncObj)
-    return nullptr;
+    return pFunc;
 
   int iType = -1;
   if (CPDF_Stream* pStream = pFuncObj->AsStream())
     iType = pStream->GetDict()->GetIntegerBy("FunctionType");
   else if (CPDF_Dictionary* pDict = pFuncObj->AsDictionary())
     iType = pDict->GetIntegerBy("FunctionType");
 
   Type type = IntegerToFunctionType(iType);
-  std::unique_ptr<CPDF_Function> pFunc;
   if (type == Type::kType0Sampled)
     pFunc.reset(new CPDF_SampledFunc());
   else if (type == Type::kType2ExpotentialInterpolation)
     pFunc.reset(new CPDF_ExpIntFunc());
   else if (type == Type::kType3Stitching)
     pFunc.reset(new CPDF_StitchFunc());
   else if (type == Type::kType4PostScript)
     pFunc.reset(new CPDF_PSFunc());
 
   if (!pFunc || !pFunc->Init(pFuncObj))
-    return nullptr;
-  return pFunc.release();
+    return std::unique_ptr<CPDF_Function>();
+  return pFunc;
 }
 
 // static
 CPDF_Function::Type CPDF_Function::IntegerToFunctionType(int iType) {
   switch (iType) {
     case 0:
     case 2:
     case 3:
     case 4:
       return static_cast<Type>(iType);
@@ skipping 83 matching lines @@
   return m_Type == Type::kType2ExpotentialInterpolation
              ? static_cast<const CPDF_ExpIntFunc*>(this)
              : nullptr;
 }
 
 const CPDF_StitchFunc* CPDF_Function::ToStitchFunc() const {
   return m_Type == Type::kType3Stitching
              ? static_cast<const CPDF_StitchFunc*>(this)
              : nullptr;
 }