Revert of Remove the document tagged code as it is unused.

core/fpdfdoc/tagged_int.h

Index: core/fpdfdoc/tagged_int.h
diff --git a/core/fpdfdoc/tagged_int.h b/core/fpdfdoc/tagged_int.h
new file mode 100644
index 0000000000000000000000000000000000000000..354a93cb76f3f4c70f5c3d9775e5b5d2ad9bc47f
--- /dev/null
+++ b/core/fpdfdoc/tagged_int.h
@@ -0,0 +1,107 @@
+// 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
+
+#ifndef CORE_FPDFDOC_TAGGED_INT_H_
+#define CORE_FPDFDOC_TAGGED_INT_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "core/fpdfdoc/include/fpdf_tagged.h"
+#include "core/fxcrt/include/cfx_retain_ptr.h"
+#include "third_party/base/stl_util.h"
+
+class CPDF_StructElementImpl;
+
+class CPDF_StructTreeImpl final : public IPDF_StructTree {
+ public:
+  explicit CPDF_StructTreeImpl(const CPDF_Document* pDoc);
+  ~CPDF_StructTreeImpl() override;
+
+  // IPDF_StructTree:
+  int CountTopElements() const override;
+  IPDF_StructElement* GetTopElement(int i) const override;
+
+  void LoadDocTree();
+  void LoadPageTree(const CPDF_Dictionary* pPageDict);
+  CPDF_StructElementImpl* AddPageNode(
+      CPDF_Dictionary* pElement,
+      std::map<CPDF_Dictionary*, CPDF_StructElementImpl*>& map,
+      int nLevel = 0);
+  FX_BOOL AddTopLevelNode(CPDF_Dictionary* pDict,
+                          CPDF_StructElementImpl* pElement);
+
+ protected:
+  const CPDF_Dictionary* const m_pTreeRoot;
+  const CPDF_Dictionary* const m_pRoleMap;
+  const CPDF_Dictionary* m_pPage;
+  std::vector<CFX_RetainPtr<CPDF_StructElementImpl>> m_Kids;
+
+  friend class CPDF_StructElementImpl;
+};
+
+class CPDF_StructElementImpl final : public IPDF_StructElement {
+ public:
+  CPDF_StructElementImpl(CPDF_StructTreeImpl* pTree,
+                         CPDF_StructElementImpl* pParent,
+                         CPDF_Dictionary* pDict);
+
+  // IPDF_StructElement
+  IPDF_StructTree* GetTree() const override;
+  const CFX_ByteString& GetType() const override;
+  IPDF_StructElement* GetParent() const override;
+  CPDF_Dictionary* GetDict() const override;
+  int CountKids() const override;
+  const CPDF_StructKid& GetKid(int index) const override;
+  CPDF_Object* GetAttr(const CFX_ByteStringC& owner,
+                       const CFX_ByteStringC& name,
+                       FX_BOOL bInheritable = FALSE,
+                       FX_FLOAT fLevel = 0.0F) override;
+  CFX_ByteString GetName(const CFX_ByteStringC& owner,
+                         const CFX_ByteStringC& name,
+                         const CFX_ByteStringC& default_value,
+                         FX_BOOL bInheritable = FALSE,
+                         int subindex = -1) override;
+  FX_ARGB GetColor(const CFX_ByteStringC& owner,
+                   const CFX_ByteStringC& name,
+                   FX_ARGB default_value,
+                   FX_BOOL bInheritable = FALSE,
+                   int subindex = -1) override;
+  FX_FLOAT GetNumber(const CFX_ByteStringC& owner,
+                     const CFX_ByteStringC& name,
+                     FX_FLOAT default_value,
+                     FX_BOOL bInheritable = FALSE,
+                     int subindex = -1) override;
+  int GetInteger(const CFX_ByteStringC& owner,
+                 const CFX_ByteStringC& name,
+                 int default_value,
+                 FX_BOOL bInheritable = FALSE,
+                 int subindex = -1) override;
+
+  void LoadKids(CPDF_Dictionary* pDict);
+  void LoadKid(uint32_t PageObjNum, CPDF_Object* pObj, CPDF_StructKid* pKid);
+  CPDF_Object* GetAttr(const CFX_ByteStringC& owner,
+                       const CFX_ByteStringC& name,
+                       FX_BOOL bInheritable,
+                       int subindex);
+  CPDF_StructElementImpl* Retain();
+  void Release();
+
+ protected:
+  ~CPDF_StructElementImpl() override;
+
+  int m_RefCount;
+  CPDF_StructTreeImpl* const m_pTree;
+  CPDF_StructElementImpl* const m_pParent;
+  CPDF_Dictionary* const m_pDict;
+  CFX_ByteString m_Type;
+  std::vector<CPDF_StructKid> m_Kids;
+
+  friend class CPDF_StructTreeImpl;
+};
+
+#endif  // CORE_FPDFDOC_TAGGED_INT_H_