Revert of Make the CPDFXFA_App non-global

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 17 matching lines @@
   CPDF_TestDocument() : CPDF_Document(std::unique_ptr<CPDF_Parser>()) {}
 
   void SetRoot(CPDF_Dictionary* root) { m_pRootDict = root; }
   CPDF_IndirectObjectHolder* GetHolder() { return this; }
 };
 
 #ifdef PDF_ENABLE_XFA
 class CPDF_TestXFADocument : public CPDFXFA_Document {
  public:
   CPDF_TestXFADocument()
-      : CPDFXFA_Document(pdfium::MakeUnique<CPDF_TestDocument>()) {}
+      : CPDFXFA_Document(pdfium::MakeUnique<CPDF_TestDocument>(),
+                         CPDFXFA_App::GetInstance()) {}
 
   void SetRoot(CPDF_Dictionary* root) {
     reinterpret_cast<CPDF_TestDocument*>(GetPDFDoc())->SetRoot(root);
   }
 
   CPDF_IndirectObjectHolder* GetHolder() { return GetPDFDoc(); }
 };
 using CPDF_TestPdfDocument = CPDF_TestXFADocument;
 #else   // PDF_ENABLE_XFA
 using CPDF_TestPdfDocument = CPDF_TestDocument;
@@ skipping 175 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()));
   }
 }