Update CPDF_IndirectObjectHolder APIs for unique objects.

Doing so highlights a few places where ownership is dubious.
Add convenience functions to return an unowned reference to
a newly-created indirect object.

Review-Url: https://codereview.chromium.org/2419173002

12 files changed, 125 insertions, 62 deletions

diff --git a/core/fpdfapi/parser/cfdf_document.cpp b/core/fpdfapi/parser/cfdf_document.cpp
index a1518dfed0..1239fcd3ce 100644
--- a/core/fpdfapi/parser/cfdf_document.cpp
+++ b/core/fpdfapi/parser/cfdf_document.cpp
@@ -26,8 +26,7 @@ CFDF_Document::~CFDF_Document() {
 
 CFDF_Document* CFDF_Document::CreateNewDoc() {
   CFDF_Document* pDoc = new CFDF_Document;
-  pDoc->m_pRootDict = new CPDF_Dictionary(pDoc->GetByteStringPool());
-  pDoc->AddIndirectObject(pDoc->m_pRootDict);
+  pDoc->m_pRootDict = pDoc->AddIndirectDictionary(pDoc->GetByteStringPool());
   pDoc->m_pRootDict->SetFor("FDF",
                             new CPDF_Dictionary(pDoc->GetByteStringPool()));
   return pDoc;
@@ -69,7 +68,8 @@ void CFDF_Document::ParseStream(IFX_FileRead* pFile, FX_BOOL bOwnFile) {
       if (!pObj)
         break;
 
-      ReplaceIndirectObjectIfHigherGeneration(objnum, pObj);
+      // TODO(tsepez): check |pObj| ownership.
+      ReplaceIndirectObjectIfHigherGeneration(objnum, UniqueObject(pObj));
       word = parser.GetNextWord(nullptr);
       if (word != "endobj")
         break;
diff --git a/core/fpdfapi/parser/cpdf_array.cpp b/core/fpdfapi/parser/cpdf_array.cpp
index 807f62d7f3..db3b18be3e 100644
--- a/core/fpdfapi/parser/cpdf_array.cpp
+++ b/core/fpdfapi/parser/cpdf_array.cpp
@@ -152,8 +152,9 @@ void CPDF_Array::ConvertToIndirectObjectAt(size_t i,
   if (!m_Objects[i] || m_Objects[i]->IsReference())
     return;
 
-  uint32_t dwObjNum = pHolder->AddIndirectObject(m_Objects[i].release());
-  m_Objects[i] = UniqueObject(new CPDF_Reference(pHolder, dwObjNum));
+  CPDF_Object* pUnowned = pHolder->AddIndirectObject(std::move(m_Objects[i]));
+  m_Objects[i] =
+      UniqueObject(new CPDF_Reference(pHolder, pUnowned->GetObjNum()));
 }
 
 void CPDF_Array::SetAt(size_t i, CPDF_Object* pObj) {
@@ -205,3 +206,8 @@ void CPDF_Array::AddReference(CPDF_IndirectObjectHolder* pDoc,
                               uint32_t objnum) {
   Add(new CPDF_Reference(pDoc, objnum));
 }
+
+void CPDF_Array::AddReference(CPDF_IndirectObjectHolder* pDoc,
+                              const CPDF_Object* pObj) {
+  AddReference(pDoc, pObj->GetObjNum());
+}
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
index f473e26800..18f1c00753 100644
--- a/core/fpdfapi/parser/cpdf_array.h
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -54,6 +54,7 @@ class CPDF_Array : public CPDF_Object {
   void AddString(const CFX_ByteString& str);
   void AddName(const CFX_ByteString& str);
   void AddReference(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum);
+  void AddReference(CPDF_IndirectObjectHolder* pDoc, const CPDF_Object* pObj);
 
   iterator begin() { return m_Objects.begin(); }
   iterator end() { return m_Objects.end(); }
diff --git a/core/fpdfapi/parser/cpdf_array_unittest.cpp b/core/fpdfapi/parser/cpdf_array_unittest.cpp
index bc9f578021..a3a27fc4ce 100644
--- a/core/fpdfapi/parser/cpdf_array_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_array_unittest.cpp
@@ -113,10 +113,11 @@ TEST(cpdf_array, Clone) {
     for (size_t i = 0; i < kNumOfRows; ++i) {
       CPDF_Array* arr_elem = new CPDF_Array;
       for (size_t j = 0; j < kNumOfRowElems; ++j) {
-        CPDF_Number* obj = new CPDF_Number(elems[i][j]);
-        // Starts object number from 1.
+        UniqueObject obj(new CPDF_Number(elems[i][j]));
+        // Object number starts from 1.
         int obj_num = i * kNumOfRowElems + j + 1;
-        obj_holder->ReplaceIndirectObjectIfHigherGeneration(obj_num, obj);
+        obj_holder->ReplaceIndirectObjectIfHigherGeneration(obj_num,
+                                                            std::move(obj));
         arr_elem->InsertAt(j, new CPDF_Reference(obj_holder.get(), obj_num));
       }
       arr->InsertAt(i, arr_elem);
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index 980c94d325..9629c204bb 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -1771,8 +1771,9 @@ CPDF_Dictionary* CPDF_DataAvail::GetPage(int index) {
       if (!pPageDict)
         return nullptr;
 
-      if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(dwObjNum,
-                                                                pPageDict)) {
+      // TODO(tsepez): check |pPageDict| ownership.
+      if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(
+              dwObjNum, UniqueObject(pPageDict))) {
         return nullptr;
       }
       return pPageDict->GetDict();
diff --git a/core/fpdfapi/parser/cpdf_dictionary.cpp b/core/fpdfapi/parser/cpdf_dictionary.cpp
index 435eee7248..0f03947ebd 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.cpp
+++ b/core/fpdfapi/parser/cpdf_dictionary.cpp
@@ -188,8 +188,8 @@ void CPDF_Dictionary::ConvertToIndirectObjectFor(
   if (it == m_Map.end() || it->second->IsReference())
     return;
 
-  uint32_t objnum = pHolder->AddIndirectObject(it->second.release());
-  it->second = UniqueReference(new CPDF_Reference(pHolder, objnum));
+  CPDF_Object* pObj = pHolder->AddIndirectObject(std::move(it->second));
+  it->second = UniqueReference(new CPDF_Reference(pHolder, pObj->GetObjNum()));
 }
 
 void CPDF_Dictionary::RemoveFor(const CFX_ByteString& key) {
@@ -229,6 +229,12 @@ void CPDF_Dictionary::SetReferenceFor(const CFX_ByteString& key,
   SetFor(key, new CPDF_Reference(pDoc, objnum));
 }
 
+void CPDF_Dictionary::SetReferenceFor(const CFX_ByteString& key,
+                                      CPDF_IndirectObjectHolder* pDoc,
+                                      const CPDF_Object* pObj) {
+  SetReferenceFor(key, pDoc, pObj->GetObjNum());
+}
+
 void CPDF_Dictionary::SetNumberFor(const CFX_ByteString& key, FX_FLOAT f) {
   SetFor(key, new CPDF_Number(f));
 }
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
index 6265522997..3e55812794 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.h
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -67,6 +67,9 @@ class CPDF_Dictionary : public CPDF_Object {
   void SetReferenceFor(const CFX_ByteString& key,
                        CPDF_IndirectObjectHolder* pDoc,
                        uint32_t objnum);
+  void SetReferenceFor(const CFX_ByteString& key,
+                       CPDF_IndirectObjectHolder* pDoc,
+                       const CPDF_Object* objnum);
   void SetRectFor(const CFX_ByteString& key, const CFX_FloatRect& rect);
   void SetMatrixFor(const CFX_ByteString& key, const CFX_Matrix& matrix);
   void SetBooleanFor(const CFX_ByteString& key, bool bValue);
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index c5f64a790c..fdd395e351 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -256,7 +256,7 @@ int InsertDeletePDFPage(CPDF_Document* pDoc,
       if (nPagesToGo == 0) {
         if (bInsert) {
           pKidList->InsertAt(i, new CPDF_Reference(pDoc, pPage->GetObjNum()));
-          pPage->SetReferenceFor("Parent", pDoc, pPages->GetObjNum());
+          pPage->SetReferenceFor("Parent", pDoc, pPages);
         } else {
           pKidList->RemoveAt(i);
         }
@@ -307,7 +307,7 @@ int InsertNewPage(CPDF_Document* pDoc,
     }
     pPagesList->Add(new CPDF_Reference(pDoc, pPageDict->GetObjNum()));
     pPages->SetIntegerFor("Count", nPages + 1);
-    pPageDict->SetReferenceFor("Parent", pDoc, pPages->GetObjNum());
+    pPageDict->SetReferenceFor("Parent", pDoc, pPages);
   } else {
     std::set<CPDF_Dictionary*> stack = {pPages};
     if (InsertDeletePDFPage(pDoc, pPages, iPage, pPageDict, TRUE, &stack) < 0)
@@ -693,25 +693,23 @@ CPDF_Image* CPDF_Document::LoadImageF(CPDF_Object* pObj) {
 
 void CPDF_Document::CreateNewDoc() {
   ASSERT(!m_pRootDict && !m_pInfoDict);
-  m_pRootDict = new CPDF_Dictionary(m_pByteStringPool);
+  m_pRootDict = AddIndirectDictionary(m_pByteStringPool);
   m_pRootDict->SetNameFor("Type", "Catalog");
-  AddIndirectObject(m_pRootDict);
 
-  CPDF_Dictionary* pPages = new CPDF_Dictionary(m_pByteStringPool);
+  CPDF_Dictionary* pPages = AddIndirectDictionary(m_pByteStringPool);
   pPages->SetNameFor("Type", "Pages");
   pPages->SetNumberFor("Count", 0);
   pPages->SetFor("Kids", new CPDF_Array);
-  m_pRootDict->SetReferenceFor("Pages", this, AddIndirectObject(pPages));
-  m_pInfoDict = new CPDF_Dictionary(m_pByteStringPool);
-  AddIndirectObject(m_pInfoDict);
+
+  m_pRootDict->SetReferenceFor("Pages", this, pPages);
+  m_pInfoDict = AddIndirectDictionary(m_pByteStringPool);
 }
 
 CPDF_Dictionary* CPDF_Document::CreateNewPage(int iPage) {
-  CPDF_Dictionary* pDict = new CPDF_Dictionary(m_pByteStringPool);
+  CPDF_Dictionary* pDict = AddIndirectDictionary(m_pByteStringPool);
   pDict->SetNameFor("Type", "Page");
-  uint32_t dwObjNum = AddIndirectObject(pDict);
   if (InsertNewPage(this, iPage, pDict, m_PageList) < 0) {
-    ReleaseIndirectObject(dwObjNum);
+    DeleteIndirectObject(pDict->GetObjNum());
     return nullptr;
   }
   return pDict;
@@ -750,7 +748,8 @@ size_t CPDF_Document::CalculateEncodingDict(int charset,
   }
   if (i == FX_ArraySize(g_FX_CharsetUnicodes))
     return i;
-  CPDF_Dictionary* pEncodingDict = new CPDF_Dictionary(m_pByteStringPool);
+
+  CPDF_Dictionary* pEncodingDict = AddIndirectDictionary(m_pByteStringPool);
   pEncodingDict->SetNameFor("BaseEncoding", "WinAnsiEncoding");
   CPDF_Array* pArray = new CPDF_Array;
   pArray->AddInteger(128);
@@ -760,9 +759,7 @@ size_t CPDF_Document::CalculateEncodingDict(int charset,
     pArray->AddName(name.IsEmpty() ? ".notdef" : name);
   }
   pEncodingDict->SetFor("Differences", pArray);
-  pBaseDict->SetReferenceFor("Encoding", this,
-                             AddIndirectObject(pEncodingDict));
-
+  pBaseDict->SetReferenceFor("Encoding", this, pEncodingDict);
   return i;
 }
 
@@ -772,7 +769,7 @@ CPDF_Dictionary* CPDF_Document::ProcessbCJK(
     FX_BOOL bVert,
     CFX_ByteString basefont,
     std::function<void(FX_WCHAR, FX_WCHAR, CPDF_Array*)> Insert) {
-  CPDF_Dictionary* pFontDict = new CPDF_Dictionary(m_pByteStringPool);
+  CPDF_Dictionary* pFontDict = AddIndirectDictionary(m_pByteStringPool);
   CFX_ByteString cmap;
   CFX_ByteString ordering;
   int supplement = 0;
@@ -822,14 +819,17 @@ CPDF_Dictionary* CPDF_Document::ProcessbCJK(
   pFontDict->SetNameFor("Type", "Font");
   pFontDict->SetNameFor("Subtype", "CIDFontType2");
   pFontDict->SetNameFor("BaseFont", basefont);
+
   CPDF_Dictionary* pCIDSysInfo = new CPDF_Dictionary(m_pByteStringPool);
   pCIDSysInfo->SetStringFor("Registry", "Adobe");
   pCIDSysInfo->SetStringFor("Ordering", ordering);
   pCIDSysInfo->SetIntegerFor("Supplement", supplement);
   pFontDict->SetFor("CIDSystemInfo", pCIDSysInfo);
+
   CPDF_Array* pArray = new CPDF_Array;
   pBaseDict->SetFor("DescendantFonts", pArray);
-  pArray->AddReference(this, AddIndirectObject(pFontDict));
+
+  pArray->AddReference(this, pFontDict);
   return pFontDict;
 }
 
@@ -847,7 +847,7 @@ CPDF_Font* CPDF_Document::AddFont(CFX_Font* pFont, int charset, FX_BOOL bVert) {
       CalculateFlags(pFont->IsBold(), pFont->IsItalic(), pFont->IsFixedWidth(),
                      false, false, charset == FXFONT_SYMBOL_CHARSET);
 
-  CPDF_Dictionary* pBaseDict = new CPDF_Dictionary(m_pByteStringPool);
+  CPDF_Dictionary* pBaseDict = AddIndirectDictionary(m_pByteStringPool);
   pBaseDict->SetNameFor("Type", "Font");
   std::unique_ptr<CFX_UnicodeEncoding> pEncoding(
       new CFX_UnicodeEncoding(pFont));
@@ -888,7 +888,6 @@ CPDF_Font* CPDF_Document::AddFont(CFX_Font* pFont, int charset, FX_BOOL bVert) {
                                                 end, widthArr);
                             });
   }
-  AddIndirectObject(pBaseDict);
   int italicangle =
       pFont->GetSubstFont() ? pFont->GetSubstFont()->m_ItalicAngle : 0;
   FX_RECT bbox;
@@ -916,8 +915,11 @@ CPDF_Font* CPDF_Document::AddFont(CFX_Font* pFont, int charset, FX_BOOL bVert) {
   CPDF_Dictionary* pFontDesc =
       CalculateFontDesc(this, basefont, flags, italicangle, pFont->GetAscent(),
                         pFont->GetDescent(), pBBox, nStemV);
+
+  // TODO(tsepez): check |pFontDesc| ownership.
   pFontDict->SetReferenceFor("FontDescriptor", this,
-                             AddIndirectObject(pFontDesc));
+                             AddIndirectObject(UniqueDictionary(pFontDesc)));
+
   return LoadFont(pBaseDict);
 }
 
@@ -979,7 +981,7 @@ CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTA* pLogFont,
                  ptm->otmrcFontBox.right, ptm->otmrcFontBox.top};
   FX_Free(tm_buf);
   basefont.Replace(" ", "");
-  CPDF_Dictionary* pBaseDict = new CPDF_Dictionary(m_pByteStringPool);
+  CPDF_Dictionary* pBaseDict = AddIndirectDictionary(m_pByteStringPool);
   pBaseDict->SetNameFor("Type", "Font");
   CPDF_Dictionary* pFontDict = pBaseDict;
   if (!bCJK) {
@@ -1004,7 +1006,6 @@ CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTA* pLogFont,
                       InsertWidthArray(hDC, start, end, widthArr);
                     });
   }
-  AddIndirectObject(pBaseDict);
   CPDF_Array* pBBox = new CPDF_Array;
   for (int i = 0; i < 4; i++)
     pBBox->AddInteger(bbox[i]);
@@ -1012,8 +1013,11 @@ CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTA* pLogFont,
       CalculateFontDesc(this, basefont, flags, italicangle, ascend, descend,
                         pBBox, pLogFont->lfWeight / 5);
   pFontDesc->SetIntegerFor("CapHeight", capheight);
+
+  // TODO(tsepez): check |pFontDesc| ownership.
   pFontDict->SetReferenceFor("FontDescriptor", this,
-                             AddIndirectObject(pFontDesc));
+                             AddIndirectObject(UniqueObject(pFontDesc)));
+
   hFont = SelectObject(hDC, hFont);
   DeleteObject(hFont);
   DeleteDC(hDC);
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp b/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
index 6e549de5a7..49567e50a1 100644
--- a/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
@@ -6,8 +6,11 @@
 
 #include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
 
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/parser/cpdf_object.h"
 #include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
 
 CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder() : m_LastObjNum(0) {}
 
@@ -42,35 +45,59 @@ CPDF_Object* CPDF_IndirectObjectHolder::ParseIndirectObject(uint32_t objnum) {
   return nullptr;
 }
 
-uint32_t CPDF_IndirectObjectHolder::AddIndirectObject(CPDF_Object* pObj) {
+CPDF_Object* CPDF_IndirectObjectHolder::AddIndirectObject(UniqueObject pObj) {
   if (pObj->m_ObjNum)
-    return pObj->m_ObjNum;
+    return pObj.release();  // TODO(tsepez): shouldn't happen, stop this leak.
 
-  m_LastObjNum++;
+  pObj->m_ObjNum = ++m_LastObjNum;
   m_IndirectObjs[m_LastObjNum].release();  // TODO(tsepez): stop this leak.
-  m_IndirectObjs[m_LastObjNum].reset(pObj);
-  pObj->m_ObjNum = m_LastObjNum;
-  return m_LastObjNum;
+  m_IndirectObjs[m_LastObjNum].reset(pObj.release());  // Changes deleters.
+  return m_IndirectObjs[m_LastObjNum].get();
+}
+
+CPDF_Array* CPDF_IndirectObjectHolder::AddIndirectArray() {
+  return ToArray(AddIndirectObject(UniqueObject(new CPDF_Array())));
+}
+
+CPDF_Dictionary* CPDF_IndirectObjectHolder::AddIndirectDictionary() {
+  return ToDictionary(AddIndirectObject(UniqueObject(new CPDF_Dictionary())));
+}
+
+CPDF_Dictionary* CPDF_IndirectObjectHolder::AddIndirectDictionary(
+    const CFX_WeakPtr<CFX_ByteStringPool>& pPool) {
+  return ToDictionary(
+      AddIndirectObject(UniqueObject(new CPDF_Dictionary(pPool))));
+}
+
+CPDF_Stream* CPDF_IndirectObjectHolder::AddIndirectStream() {
+  return ToStream(AddIndirectObject(UniqueObject(new CPDF_Stream())));
+}
+
+CPDF_Stream* CPDF_IndirectObjectHolder::AddIndirectStream(
+    uint8_t* pData,
+    uint32_t size,
+    CPDF_Dictionary* pDict) {
+  return ToStream(
+      AddIndirectObject(UniqueObject(new CPDF_Stream(pData, size, pDict))));
 }
 
 bool CPDF_IndirectObjectHolder::ReplaceIndirectObjectIfHigherGeneration(
     uint32_t objnum,
-    CPDF_Object* pObj) {
+    UniqueObject pObj) {
   if (!objnum || !pObj)
     return false;
 
   CPDF_Object* pOldObj = GetIndirectObject(objnum);
-  if (pOldObj && pObj->GetGenNum() <= pOldObj->GetGenNum()) {
-    delete pObj;
+  if (pOldObj && pObj->GetGenNum() <= pOldObj->GetGenNum())
     return false;
-  }
+
   pObj->m_ObjNum = objnum;
-  m_IndirectObjs[objnum].reset(pObj);
+  m_IndirectObjs[objnum].reset(pObj.release());  // Changes deleters.
   m_LastObjNum = std::max(m_LastObjNum, objnum);
   return true;
 }
 
-void CPDF_IndirectObjectHolder::ReleaseIndirectObject(uint32_t objnum) {
+void CPDF_IndirectObjectHolder::DeleteIndirectObject(uint32_t objnum) {
   CPDF_Object* pObj = GetIndirectObject(objnum);
   if (!pObj || pObj->GetObjNum() == CPDF_Object::kInvalidObjNum)
     return;
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder.h b/core/fpdfapi/parser/cpdf_indirect_object_holder.h
index da4e942b5d..074e428d43 100644
--- a/core/fpdfapi/parser/cpdf_indirect_object_holder.h
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder.h
@@ -10,9 +10,14 @@
 #include <map>
 #include <memory>
 
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/cfx_string_pool_template.h"
+#include "core/fxcrt/cfx_weak_ptr.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPDF_Object;
+class CPDF_Array;
+class CPDF_Dictionary;
+class CPDF_Stream;
 
 class CPDF_IndirectObjectHolder {
  public:
@@ -24,12 +29,23 @@ class CPDF_IndirectObjectHolder {
 
   CPDF_Object* GetIndirectObject(uint32_t objnum) const;
   CPDF_Object* GetOrParseIndirectObject(uint32_t objnum);
-  void ReleaseIndirectObject(uint32_t objnum);
+  void DeleteIndirectObject(uint32_t objnum);
+
+  // Take ownership of |pObj|, returns unowned pointer to it.
+  CPDF_Object* AddIndirectObject(UniqueObject pObj);
+
+  // Adds and owns a new object, returns unowned pointer to it.
+  CPDF_Array* AddIndirectArray();
+  CPDF_Dictionary* AddIndirectDictionary();
+  CPDF_Dictionary* AddIndirectDictionary(
+      const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
+  CPDF_Stream* AddIndirectStream();
+  CPDF_Stream* AddIndirectStream(uint8_t* pData,
+                                 uint32_t size,
+                                 CPDF_Dictionary* pDict);
 
-  // Take ownership of |pObj|.
-  uint32_t AddIndirectObject(CPDF_Object* pObj);
   bool ReplaceIndirectObjectIfHigherGeneration(uint32_t objnum,
-                                               CPDF_Object* pObj);
+                                               UniqueObject pObj);
 
   uint32_t GetLastObjNum() const { return m_LastObjNum; }
   void SetLastObjNum(uint32_t objnum) { m_LastObjNum = objnum; }
@@ -42,6 +58,8 @@ class CPDF_IndirectObjectHolder {
 
  private:
   uint32_t m_LastObjNum;
+
+  // Ordinary deleter, not Release().
   std::map<uint32_t, std::unique_ptr<CPDF_Object>> m_IndirectObjs;
 };
 
diff --git a/core/fpdfapi/parser/cpdf_object_unittest.cpp b/core/fpdfapi/parser/cpdf_object_unittest.cpp
index e5a5f54915..b47a06fbfc 100644
--- a/core/fpdfapi/parser/cpdf_object_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_object_unittest.cpp
@@ -101,7 +101,7 @@ class PDFObjectsTest : public testing::Test {
                       m_ArrayObj->Clone(),       m_DictObj->Clone(),
                       stream_obj->Clone()};
     for (size_t i = 0; i < m_IndirectObjs.size(); ++i) {
-      m_ObjHolder->AddIndirectObject(m_IndirectObjs[i]);
+      m_ObjHolder->AddIndirectObject(UniqueObject(m_IndirectObjs[i]));
       m_RefObjs.emplace_back(new CPDF_Reference(
           m_ObjHolder.get(), m_IndirectObjs[i]->GetObjNum()));
     }
@@ -730,8 +730,8 @@ TEST(PDFArrayTest, AddReferenceAndGetObjectAt) {
   // Create two arrays of references by different AddReference() APIs.
   for (size_t i = 0; i < FX_ArraySize(indirect_objs); ++i) {
     // All the indirect objects inserted will be owned by holder.
-    holder->ReplaceIndirectObjectIfHigherGeneration(obj_nums[i],
-                                                    indirect_objs[i]);
+    holder->ReplaceIndirectObjectIfHigherGeneration(
+        obj_nums[i], UniqueObject(indirect_objs[i]));
     arr->AddReference(holder.get(), obj_nums[i]);
     arr1->AddReference(holder.get(), indirect_objs[i]->GetObjNum());
   }
@@ -841,9 +841,8 @@ TEST(PDFObjectTest, CloneCheckLoop) {
   {
     CPDF_IndirectObjectHolder objects_holder;
     // Create an object with a reference loop.
-    CPDF_Dictionary* dict_obj = new CPDF_Dictionary();
+    CPDF_Dictionary* dict_obj = objects_holder.AddIndirectDictionary();
     CPDF_Array* arr_obj = new CPDF_Array;
-    objects_holder.AddIndirectObject(dict_obj);
     EXPECT_EQ(1u, dict_obj->GetObjNum());
     dict_obj->SetFor("arr", arr_obj);
     arr_obj->InsertAt(
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index 40a615fa47..d9c892f133 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -955,21 +955,18 @@ FX_BOOL CPDF_Parser::RebuildCrossRef() {
 }
 
 FX_BOOL CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, FX_BOOL bMainXRef) {
-  std::unique_ptr<CPDF_Object> pObject(
-      ParseIndirectObjectAt(m_pDocument, *pos, 0));
+  UniqueObject pObject(ParseIndirectObjectAt(m_pDocument, *pos, 0));
   if (!pObject)
     return FALSE;
 
   CPDF_Object* pUnownedObject = pObject.get();
-
   if (m_pDocument) {
     CPDF_Dictionary* pRootDict = m_pDocument->GetRoot();
     if (pRootDict && pRootDict->GetObjNum() == pObject->m_ObjNum)
       return FALSE;
-    // Takes ownership of object (std::move someday).
     uint32_t objnum = pObject->m_ObjNum;
     if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(
-            objnum, pObject.release())) {
+            objnum, std::move(pObject))) {
       return FALSE;
     }
   }