Update CPDF_IndirectObjectHolder APIs for unique objects

fpdfsdk/fpdfdoc_unittest.cpp

 // 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.
 
 #include "public/fpdf_doc.h"
 
 #include <memory>
 #include <vector>
 
 #include "core/fpdfapi/cpdf_modulemgr.h"
@@ skipping 62 matching lines @@
     m_pRootObj.reset();
     m_pIndirectObjs = nullptr;
     m_pDoc.reset();
     CPDF_ModuleMgr::Destroy();
   }
 
   std::vector<DictObjInfo> CreateDictObjs(int num) {
     std::vector<DictObjInfo> info;
     for (int i = 0; i < num; ++i) {
       // Objects created will be released by the document.
-      CPDF_Dictionary* obj = new CPDF_Dictionary();
-      info.push_back({m_pIndirectObjs->AddIndirectObject(obj), obj});
+      CPDF_Dictionary* obj = m_pIndirectObjs->AddIndirectDictionary();
+      info.push_back({obj->GetObjNum(), obj});
     }
     return info;
   }
 
  protected:
   std::unique_ptr<CPDF_TestPdfDocument> m_pDoc;
   CPDF_IndirectObjectHolder* m_pIndirectObjs;
   std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> m_pRootObj;
 };
 
@@ skipping 130 matching lines @@
     // Title with no match.
     std::unique_ptr<unsigned short, pdfium::FreeDeleter> title =
         GetFPDFWideString(L"Chapter 8");
     EXPECT_EQ(nullptr, FPDFBookmark_Find(m_pDoc.get(), title.get()));
 
     // Title with a match.
     title = GetFPDFWideString(L"Chapter 3");
     EXPECT_EQ(bookmarks[3].obj, FPDFBookmark_Find(m_pDoc.get(), title.get()));
   }
 }