Merge to XFA: Refactor CPDF_Object and its subclasses.

Mainly use virtual functions to replace functions with switch statements.
Also remove a few unused functions and make some format changes.

BUG=pdfium:63
TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1634373003 .

(cherry picked from commit df1ab41e000069dda7bf21527308f3bf41e126ca)

Review URL: https://codereview.chromium.org/1650493003 .

4 files changed, 600 insertions, 699 deletions

diff --git a/core/include/fpdfapi/fpdf_objects.h b/core/include/fpdfapi/fpdf_objects.h
index 0478acc3e0..86035a86ad 100644
--- a/core/include/fpdfapi/fpdf_objects.h
+++ b/core/include/fpdfapi/fpdf_objects.h
@@ -44,65 +44,61 @@ class CPDF_Object {
     REFERENCE
   };
 
-  Type GetType() const { return m_Type; }
+  virtual Type GetType() const = 0;
   FX_DWORD GetObjNum() const { return m_ObjNum; }
   FX_DWORD GetGenNum() const { return m_GenNum; }
 
-  FX_BOOL IsIdentical(CPDF_Object* pObj) const;
-  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const;
-  CPDF_Object* CloneRef(CPDF_IndirectObjectHolder* pObjs) const;
+  virtual CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const = 0;
+  virtual CPDF_Object* GetDirect() const {
+    return const_cast<CPDF_Object*>(this);
+  }
 
-  CPDF_Object* GetDirect() const;
   FX_BOOL IsModified() const { return FALSE; }
-
   void Release();
 
-  CFX_ByteString GetString() const;
-  CFX_ByteStringC GetConstString() const;
-  CFX_WideString GetUnicodeText(CFX_CharMap* pCharMap = NULL) const;
-  FX_FLOAT GetNumber() const;
-  FX_FLOAT GetNumber16() const;
-  int GetInteger() const;
-  CPDF_Dictionary* GetDict() const;
-  CPDF_Array* GetArray() const;
-
-  void SetString(const CFX_ByteString& str);
-  void SetUnicodeText(const FX_WCHAR* pUnicodes, int len = -1);
-
-  bool IsArray() const { return m_Type == ARRAY; }
-  bool IsBoolean() const { return m_Type == BOOLEAN; }
-  bool IsDictionary() const { return m_Type == DICTIONARY; }
-  bool IsName() const { return m_Type == NAME; }
-  bool IsNumber() const { return m_Type == NUMBER; }
-  bool IsReference() const { return m_Type == REFERENCE; }
-  bool IsStream() const { return m_Type == STREAM; }
-  bool IsString() const { return m_Type == STRING; }
-
-  CPDF_Array* AsArray();
-  const CPDF_Array* AsArray() const;
-  CPDF_Boolean* AsBoolean();
-  const CPDF_Boolean* AsBoolean() const;
-  CPDF_Dictionary* AsDictionary();
-  const CPDF_Dictionary* AsDictionary() const;
-  CPDF_Name* AsName();
-  const CPDF_Name* AsName() const;
-  CPDF_Number* AsNumber();
-  const CPDF_Number* AsNumber() const;
-  CPDF_Reference* AsReference();
-  const CPDF_Reference* AsReference() const;
-  CPDF_Stream* AsStream();
-  const CPDF_Stream* AsStream() const;
-  CPDF_String* AsString();
-  const CPDF_String* AsString() const;
+  virtual CFX_ByteString GetString() const { return CFX_ByteString(); }
+  virtual CFX_ByteStringC GetConstString() const { return CFX_ByteStringC(); }
+  virtual CFX_WideString GetUnicodeText(CFX_CharMap* pCharMap = nullptr) const {
+    return CFX_WideString();
+  }
+  virtual FX_FLOAT GetNumber() const { return 0; }
+  virtual int GetInteger() const { return 0; }
+  virtual CPDF_Dictionary* GetDict() const { return nullptr; }
+  virtual CPDF_Array* GetArray() const { return nullptr; }
+
+  virtual void SetString(const CFX_ByteString& str) { ASSERT(FALSE); }
+
+  virtual bool IsArray() const { return false; }
+  virtual bool IsBoolean() const { return false; }
+  virtual bool IsDictionary() const { return false; }
+  virtual bool IsName() const { return false; }
+  virtual bool IsNumber() const { return false; }
+  virtual bool IsReference() const { return false; }
+  virtual bool IsStream() const { return false; }
+  virtual bool IsString() const { return false; }
+
+  virtual CPDF_Array* AsArray() { return nullptr; }
+  virtual const CPDF_Array* AsArray() const { return nullptr; }
+  virtual CPDF_Boolean* AsBoolean() { return nullptr; }
+  virtual const CPDF_Boolean* AsBoolean() const { return nullptr; }
+  virtual CPDF_Dictionary* AsDictionary() { return nullptr; }
+  virtual const CPDF_Dictionary* AsDictionary() const { return nullptr; }
+  virtual CPDF_Name* AsName() { return nullptr; }
+  virtual const CPDF_Name* AsName() const { return nullptr; }
+  virtual CPDF_Number* AsNumber() { return nullptr; }
+  virtual const CPDF_Number* AsNumber() const { return nullptr; }
+  virtual CPDF_Reference* AsReference() { return nullptr; }
+  virtual const CPDF_Reference* AsReference() const { return nullptr; }
+  virtual CPDF_Stream* AsStream() { return nullptr; }
+  virtual const CPDF_Stream* AsStream() const { return nullptr; }
+  virtual CPDF_String* AsString() { return nullptr; }
+  virtual const CPDF_String* AsString() const { return nullptr; }
 
  protected:
-  explicit CPDF_Object(Type type) : m_Type(type), m_ObjNum(0), m_GenNum(0) {}
-  ~CPDF_Object() {}
-  void Destroy();
+  CPDF_Object() : m_ObjNum(0), m_GenNum(0) {}
+  virtual ~CPDF_Object() {}
+  void Destroy() { delete this; }
 
-  const CPDF_Object* GetBasicObject() const;
-
-  const Type m_Type;
   FX_DWORD m_ObjNum;
   FX_DWORD m_GenNum;
 
@@ -111,66 +107,73 @@ class CPDF_Object {
   friend class CPDF_SyntaxParser;
 
  private:
-  CPDF_Object* CloneInternal(FX_BOOL bDirect,
-                             std::set<FX_DWORD>* visited) const;
+  CPDF_Object(const CPDF_Object& src) {}
 };
+
 class CPDF_Boolean : public CPDF_Object {
  public:
-  CPDF_Boolean() : CPDF_Object(BOOLEAN), m_bValue(false) {}
-  explicit CPDF_Boolean(FX_BOOL value)
-      : CPDF_Object(BOOLEAN), m_bValue(value) {}
+  CPDF_Boolean() : m_bValue(false) {}
+  explicit CPDF_Boolean(FX_BOOL value) : m_bValue(value) {}
 
-  FX_BOOL Identical(CPDF_Boolean* pOther) const {
-    return m_bValue == pOther->m_bValue;
+  // CPDF_Object.
+  Type GetType() const override { return BOOLEAN; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override {
+    return new CPDF_Boolean(m_bValue);
   }
-
-  CFX_ByteString GetString() const { return m_bValue ? "true" : "false"; }
-  FX_BOOL GetValue() const { return m_bValue; }
+  CFX_ByteString GetString() const override {
+    return m_bValue ? "true" : "false";
+  }
+  int GetInteger() const override { return m_bValue; }
+  void SetString(const CFX_ByteString& str) override {
+    m_bValue = (str == "true");
+  }
+  bool IsBoolean() const override { return true; }
+  CPDF_Boolean* AsBoolean() override { return this; }
+  const CPDF_Boolean* AsBoolean() const override { return this; }
 
  protected:
+  ~CPDF_Boolean() {}
+
   FX_BOOL m_bValue;
-  friend class CPDF_Object;
 };
+
 inline CPDF_Boolean* ToBoolean(CPDF_Object* obj) {
   return obj ? obj->AsBoolean() : nullptr;
 }
+
 inline const CPDF_Boolean* ToBoolean(const CPDF_Object* obj) {
   return obj ? obj->AsBoolean() : nullptr;
 }
 
 class CPDF_Number : public CPDF_Object {
  public:
-  CPDF_Number() : CPDF_Object(NUMBER), m_bInteger(TRUE), m_Integer(0) {}
-
-  explicit CPDF_Number(int value);
-
-  explicit CPDF_Number(FX_FLOAT value);
-
+  CPDF_Number() : m_bInteger(TRUE), m_Integer(0) {}
+  explicit CPDF_Number(int value) : m_bInteger(TRUE), m_Integer(value) {}
+  explicit CPDF_Number(FX_FLOAT value) : m_bInteger(FALSE), m_Float(value) {}
   explicit CPDF_Number(const CFX_ByteStringC& str);
 
-  FX_BOOL Identical(CPDF_Number* pOther) const;
-
-  CFX_ByteString GetString() const;
-
-  void SetString(const CFX_ByteStringC& str);
-
-  FX_BOOL IsInteger() const { return m_bInteger; }
-
-  int GetInteger() const { return m_bInteger ? m_Integer : (int)m_Float; }
-
-  FX_FLOAT GetNumber() const {
-    return m_bInteger ? (FX_FLOAT)m_Integer : m_Float;
+  // CPDF_Object.
+  Type GetType() const override { return NUMBER; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override {
+    return m_bInteger ? new CPDF_Number(m_Integer) : new CPDF_Number(m_Float);
   }
-
-  void SetNumber(FX_FLOAT value);
-
-  FX_FLOAT GetNumber16() const { return GetNumber(); }
-
-  FX_FLOAT GetFloat() const {
-    return m_bInteger ? (FX_FLOAT)m_Integer : m_Float;
+  CFX_ByteString GetString() const override;
+  FX_FLOAT GetNumber() const override {
+    return m_bInteger ? static_cast<FX_FLOAT>(m_Integer) : m_Float;
   }
+  int GetInteger() const override {
+    return m_bInteger ? m_Integer : static_cast<int>(m_Float);
+  }
+  void SetString(const CFX_ByteString& str) override;
+  bool IsNumber() const override { return true; }
+  CPDF_Number* AsNumber() override { return this; }
+  const CPDF_Number* AsNumber() const override { return this; }
+
+  FX_BOOL IsInteger() { return m_bInteger; }
 
  protected:
+  ~CPDF_Number() {}
+
   FX_BOOL m_bInteger;
 
   union {
@@ -178,141 +181,149 @@ class CPDF_Number : public CPDF_Object {
 
     FX_FLOAT m_Float;
   };
-  friend class CPDF_Object;
 };
+
 inline CPDF_Number* ToNumber(CPDF_Object* obj) {
   return obj ? obj->AsNumber() : nullptr;
 }
+
 inline const CPDF_Number* ToNumber(const CPDF_Object* obj) {
   return obj ? obj->AsNumber() : nullptr;
 }
 
 class CPDF_String : public CPDF_Object {
  public:
-  CPDF_String() : CPDF_Object(STRING), m_bHex(FALSE) {}
-
+  CPDF_String() : m_bHex(FALSE) {}
   CPDF_String(const CFX_ByteString& str, FX_BOOL bHex)
-      : CPDF_Object(STRING), m_String(str), m_bHex(bHex) {}
-
+      : m_String(str), m_bHex(bHex) {}
   explicit CPDF_String(const CFX_WideString& str);
 
-  CFX_ByteString GetString() const { return m_String; }
-
-  FX_BOOL Identical(CPDF_String* pOther) const {
-    return m_String == pOther->m_String;
+  // CPDF_Object.
+  Type GetType() const override { return STRING; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override {
+    return new CPDF_String(m_String, m_bHex);
+  }
+  CFX_ByteString GetString() const override { return m_String; }
+  CFX_ByteStringC GetConstString() const override {
+    return CFX_ByteStringC(m_String);
   }
+  CFX_WideString GetUnicodeText(CFX_CharMap* pCharMap = nullptr) const override;
+  void SetString(const CFX_ByteString& str) override { m_String = str; }
+  bool IsString() const override { return true; }
+  CPDF_String* AsString() override { return this; }
+  const CPDF_String* AsString() const override { return this; }
 
   FX_BOOL IsHex() const { return m_bHex; }
 
  protected:
-  CFX_ByteString m_String;
+  ~CPDF_String() {}
 
+  CFX_ByteString m_String;
   FX_BOOL m_bHex;
-  friend class CPDF_Object;
 };
+
 inline CPDF_String* ToString(CPDF_Object* obj) {
   return obj ? obj->AsString() : nullptr;
 }
+
 inline const CPDF_String* ToString(const CPDF_Object* obj) {
   return obj ? obj->AsString() : nullptr;
 }
 
 class CPDF_Name : public CPDF_Object {
  public:
-  explicit CPDF_Name(const CFX_ByteString& str)
-      : CPDF_Object(NAME), m_Name(str) {}
-  explicit CPDF_Name(const CFX_ByteStringC& str)
-      : CPDF_Object(NAME), m_Name(str) {}
-  explicit CPDF_Name(const FX_CHAR* str) : CPDF_Object(NAME), m_Name(str) {}
-
-  CFX_ByteString GetString() const { return m_Name; }
-
-  FX_BOOL Identical(CPDF_Name* pOther) const {
-    return m_Name == pOther->m_Name;
+  explicit CPDF_Name(const CFX_ByteString& str) : m_Name(str) {}
+  explicit CPDF_Name(const CFX_ByteStringC& str) : m_Name(str) {}
+  explicit CPDF_Name(const FX_CHAR* str) : m_Name(str) {}
+
+  // CPDF_Object.
+  Type GetType() const override { return NAME; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override {
+    return new CPDF_Name(m_Name);
   }
+  CFX_ByteString GetString() const override { return m_Name; }
+  CFX_ByteStringC GetConstString() const override {
+    return CFX_ByteStringC(m_Name);
+  }
+  CFX_WideString GetUnicodeText(CFX_CharMap* pCharMap = nullptr) const override;
+  void SetString(const CFX_ByteString& str) override { m_Name = str; }
+  bool IsName() const override { return true; }
+  CPDF_Name* AsName() override { return this; }
+  const CPDF_Name* AsName() const override { return this; }
 
  protected:
+  ~CPDF_Name() {}
+
   CFX_ByteString m_Name;
-  friend class CPDF_Object;
 };
+
 inline CPDF_Name* ToName(CPDF_Object* obj) {
   return obj ? obj->AsName() : nullptr;
 }
+
 inline const CPDF_Name* ToName(const CPDF_Object* obj) {
   return obj ? obj->AsName() : nullptr;
 }
 
 class CPDF_Array : public CPDF_Object {
  public:
-  CPDF_Array() : CPDF_Object(ARRAY) {}
+  CPDF_Array() {}
+
+  // CPDF_Object.
+  Type GetType() const override { return ARRAY; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override;
+  CPDF_Array* GetArray() const override {
+    // The method should be made non-const if we want to not be const.
+    // See bug #234.
+    return const_cast<CPDF_Array*>(this);
+  }
+  bool IsArray() const override { return true; }
+  CPDF_Array* AsArray() override { return this; }
+  const CPDF_Array* AsArray() const override { return this; }
 
   FX_DWORD GetCount() const { return m_Objects.GetSize(); }
-
   CPDF_Object* GetElement(FX_DWORD index) const;
-
   CPDF_Object* GetElementValue(FX_DWORD index) const;
-
   CFX_Matrix GetMatrix();
-
   CFX_FloatRect GetRect();
-
   CFX_ByteString GetStringAt(FX_DWORD index) const;
-
   CFX_ByteStringC GetConstStringAt(FX_DWORD index) const;
-
   int GetIntegerAt(FX_DWORD index) const;
-
   FX_FLOAT GetNumberAt(FX_DWORD index) const;
-
   CPDF_Dictionary* GetDictAt(FX_DWORD index) const;
-
   CPDF_Stream* GetStreamAt(FX_DWORD index) const;
-
   CPDF_Array* GetArrayAt(FX_DWORD index) const;
-
   FX_FLOAT GetFloatAt(FX_DWORD index) const { return GetNumberAt(index); }
 
   void SetAt(FX_DWORD index,
              CPDF_Object* pObj,
-             CPDF_IndirectObjectHolder* pObjs = NULL);
-
+             CPDF_IndirectObjectHolder* pObjs = nullptr);
   void InsertAt(FX_DWORD index,
                 CPDF_Object* pObj,
-                CPDF_IndirectObjectHolder* pObjs = NULL);
-
+                CPDF_IndirectObjectHolder* pObjs = nullptr);
   void RemoveAt(FX_DWORD index, int nCount = 1);
 
-  void Add(CPDF_Object* pObj, CPDF_IndirectObjectHolder* pObjs = NULL);
-
+  void Add(CPDF_Object* pObj, CPDF_IndirectObjectHolder* pObjs = nullptr);
   void AddNumber(FX_FLOAT f);
-
   void AddInteger(int i);
-
   void AddString(const CFX_ByteString& str);
-
   void AddName(const CFX_ByteString& str);
-
   void AddReference(CPDF_IndirectObjectHolder* pDoc, FX_DWORD objnum);
-
   void AddReference(CPDF_IndirectObjectHolder* pDoc, CPDF_Object* obj) {
     AddReference(pDoc, obj->GetObjNum());
   }
-
-  FX_FLOAT GetNumber16(FX_DWORD index) const { return GetNumberAt(index); }
-
   void AddNumber16(FX_FLOAT value) { AddNumber(value); }
 
-  FX_BOOL Identical(CPDF_Array* pOther) const;
-
  protected:
   ~CPDF_Array();
 
   CFX_ArrayTemplate<CPDF_Object*> m_Objects;
-  friend class CPDF_Object;
 };
+
 inline CPDF_Array* ToArray(CPDF_Object* obj) {
   return obj ? obj->AsArray() : nullptr;
 }
+
 inline const CPDF_Array* ToArray(const CPDF_Object* obj) {
   return obj ? obj->AsArray() : nullptr;
 }
@@ -322,44 +333,41 @@ class CPDF_Dictionary : public CPDF_Object {
   using iterator = std::map<CFX_ByteString, CPDF_Object*>::iterator;
   using const_iterator = std::map<CFX_ByteString, CPDF_Object*>::const_iterator;
 
-  CPDF_Dictionary() : CPDF_Object(DICTIONARY) {}
+  CPDF_Dictionary() {}
 
-  CPDF_Object* GetElement(const CFX_ByteStringC& key) const;
+  // CPDF_Object.
+  Type GetType() const override { return DICTIONARY; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override;
+  CPDF_Dictionary* GetDict() const override {
+    // The method should be made non-const if we want to not be const.
+    // See bug #234.
+    return const_cast<CPDF_Dictionary*>(this);
+  }
+  bool IsDictionary() const override { return true; }
+  CPDF_Dictionary* AsDictionary() override { return this; }
+  const CPDF_Dictionary* AsDictionary() const override { return this; }
 
+  size_t GetCount() const { return m_Map.size(); }
+  CPDF_Object* GetElement(const CFX_ByteStringC& key) const;
   CPDF_Object* GetElementValue(const CFX_ByteStringC& key) const;
-
   CFX_ByteString GetStringBy(const CFX_ByteStringC& key) const;
-
   CFX_ByteStringC GetConstStringBy(const CFX_ByteStringC& key) const;
-
   CFX_ByteString GetStringBy(const CFX_ByteStringC& key,
                              const CFX_ByteStringC& default_str) const;
-
   CFX_ByteStringC GetConstStringBy(const CFX_ByteStringC& key,
                                    const CFX_ByteStringC& default_str) const;
-
   CFX_WideString GetUnicodeTextBy(const CFX_ByteStringC& key,
                                   CFX_CharMap* pCharMap = NULL) const;
-
   int GetIntegerBy(const CFX_ByteStringC& key) const;
-
   int GetIntegerBy(const CFX_ByteStringC& key, int default_int) const;
-
   FX_BOOL GetBooleanBy(const CFX_ByteStringC& key,
                        FX_BOOL bDefault = FALSE) const;
-
   FX_FLOAT GetNumberBy(const CFX_ByteStringC& key) const;
-
   CPDF_Dictionary* GetDictBy(const CFX_ByteStringC& key) const;
-
   CPDF_Stream* GetStreamBy(const CFX_ByteStringC& key) const;
-
   CPDF_Array* GetArrayBy(const CFX_ByteStringC& key) const;
-
   CFX_FloatRect GetRectBy(const CFX_ByteStringC& key) const;
-
   CFX_Matrix GetMatrixBy(const CFX_ByteStringC& key) const;
-
   FX_FLOAT GetFloatBy(const CFX_ByteStringC& key) const {
     return GetNumberBy(key);
   }
@@ -368,63 +376,47 @@ class CPDF_Dictionary : public CPDF_Object {
 
   // Set* functions invalidate iterators for the element with the key |key|.
   void SetAt(const CFX_ByteStringC& key, CPDF_Object* pObj);
-
   void SetAtName(const CFX_ByteStringC& key, const CFX_ByteString& name);
-
   void SetAtString(const CFX_ByteStringC& key, const CFX_ByteString& string);
-
   void SetAtInteger(const CFX_ByteStringC& key, int i);
-
   void SetAtNumber(const CFX_ByteStringC& key, FX_FLOAT f);
-
   void SetAtReference(const CFX_ByteStringC& key,
                       CPDF_IndirectObjectHolder* pDoc,
                       FX_DWORD objnum);
-
   void SetAtReference(const CFX_ByteStringC& key,
                       CPDF_IndirectObjectHolder* pDoc,
                       CPDF_Object* obj) {
     SetAtReference(key, pDoc, obj->GetObjNum());
   }
+  void SetAtRect(const CFX_ByteStringC& key, const CFX_FloatRect& rect);
+  void SetAtMatrix(const CFX_ByteStringC& key, const CFX_Matrix& matrix);
+  void SetAtBoolean(const CFX_ByteStringC& key, FX_BOOL bValue);
 
   void AddReference(const CFX_ByteStringC& key,
                     CPDF_IndirectObjectHolder* pDoc,
                     FX_DWORD objnum);
 
-  void SetAtRect(const CFX_ByteStringC& key, const CFX_FloatRect& rect);
-
-  void SetAtMatrix(const CFX_ByteStringC& key, const CFX_Matrix& matrix);
-
-  void SetAtBoolean(const CFX_ByteStringC& key, FX_BOOL bValue);
-
   // Invalidates iterators for the element with the key |key|.
   void RemoveAt(const CFX_ByteStringC& key);
 
   // Invalidates iterators for the element with the key |oldkey|.
   void ReplaceKey(const CFX_ByteStringC& oldkey, const CFX_ByteStringC& newkey);
 
-  FX_BOOL Identical(CPDF_Dictionary* pDict) const;
-
-  size_t GetCount() const { return m_Map.size(); }
-
   iterator begin() { return m_Map.begin(); }
-
   iterator end() { return m_Map.end(); }
-
   const_iterator begin() const { return m_Map.begin(); }
-
   const_iterator end() const { return m_Map.end(); }
 
  protected:
   ~CPDF_Dictionary();
 
   std::map<CFX_ByteString, CPDF_Object*> m_Map;
-
-  friend class CPDF_Object;
 };
+
 inline CPDF_Dictionary* ToDictionary(CPDF_Object* obj) {
   return obj ? obj->AsDictionary() : nullptr;
 }
+
 inline const CPDF_Dictionary* ToDictionary(const CPDF_Object* obj) {
   return obj ? obj->AsDictionary() : nullptr;
 }
@@ -433,7 +425,17 @@ class CPDF_Stream : public CPDF_Object {
  public:
   CPDF_Stream(uint8_t* pData, FX_DWORD size, CPDF_Dictionary* pDict);
 
-  CPDF_Dictionary* GetDict() const { return m_pDict; }
+  // CPDF_Object.
+  Type GetType() const override { return STREAM; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override;
+  CPDF_Dictionary* GetDict() const override { return m_pDict; }
+  CFX_WideString GetUnicodeText(CFX_CharMap* pCharMap = nullptr) const override;
+  bool IsStream() const override { return true; }
+  CPDF_Stream* AsStream() override { return this; }
+  const CPDF_Stream* AsStream() const override { return this; }
+
+  FX_DWORD GetRawSize() const { return m_dwSize; }
+  uint8_t* GetRawData() const { return m_pDataBuf; }
 
   void SetData(const uint8_t* pData,
                FX_DWORD size,
@@ -441,13 +443,8 @@ class CPDF_Stream : public CPDF_Object {
                FX_BOOL bKeepBuf);
 
   void InitStream(uint8_t* pData, FX_DWORD size, CPDF_Dictionary* pDict);
-
   void InitStreamFromFile(IFX_FileRead* pFile, CPDF_Dictionary* pDict);
 
-  FX_BOOL Identical(CPDF_Stream* pOther) const;
-
-  FX_DWORD GetRawSize() const { return m_dwSize; }
-
   FX_BOOL ReadRawData(FX_FILESIZE start_pos,
                       uint8_t* pBuf,
                       FX_DWORD buf_size) const;
@@ -455,29 +452,26 @@ class CPDF_Stream : public CPDF_Object {
   FX_BOOL IsMemoryBased() const { return m_GenNum == kMemoryBasedGenNum; }
 
  protected:
-  friend class CPDF_Object;
-  friend class CPDF_StreamAcc;
-
   static const FX_DWORD kMemoryBasedGenNum = (FX_DWORD)-1;
+
   ~CPDF_Stream();
 
   void InitStreamInternal(CPDF_Dictionary* pDict);
 
   CPDF_Dictionary* m_pDict;
-
   FX_DWORD m_dwSize;
-
   FX_DWORD m_GenNum;
 
   union {
     uint8_t* m_pDataBuf;
-
     IFX_FileRead* m_pFile;
   };
 };
+
 inline CPDF_Stream* ToStream(CPDF_Object* obj) {
   return obj ? obj->AsStream() : nullptr;
 }
+
 inline const CPDF_Stream* ToStream(const CPDF_Object* obj) {
   return obj ? obj->AsStream() : nullptr;
 }
@@ -485,7 +479,6 @@ inline const CPDF_Stream* ToStream(const CPDF_Object* obj) {
 class CPDF_StreamAcc {
  public:
   CPDF_StreamAcc();
-
   ~CPDF_StreamAcc();
 
   void LoadAllData(const CPDF_Stream* pStream,
@@ -494,66 +487,93 @@ class CPDF_StreamAcc {
                    FX_BOOL bImageAcc = FALSE);
 
   const CPDF_Stream* GetStream() const { return m_pStream; }
-
   CPDF_Dictionary* GetDict() const {
     return m_pStream ? m_pStream->GetDict() : nullptr;
   }
-
   const uint8_t* GetData() const;
-
   FX_DWORD GetSize() const;
+  const CFX_ByteString& GetImageDecoder() const { return m_ImageDecoder; }
+  const CPDF_Dictionary* GetImageParam() const { return m_pImageParam; }
 
   uint8_t* DetachData();
 
-  const CFX_ByteString& GetImageDecoder() { return m_ImageDecoder; }
-
-  const CPDF_Dictionary* GetImageParam() { return m_pImageParam; }
-
  protected:
   uint8_t* m_pData;
-
   FX_DWORD m_dwSize;
-
   FX_BOOL m_bNewBuf;
-
   CFX_ByteString m_ImageDecoder;
-
   CPDF_Dictionary* m_pImageParam;
-
   const CPDF_Stream* m_pStream;
-
   uint8_t* m_pSrcData;
 };
 
 class CPDF_Null : public CPDF_Object {
  public:
-  CPDF_Null() : CPDF_Object(NULLOBJ) {}
+  CPDF_Null() {}
+
+  // CPDF_Object.
+  Type GetType() const override { return NULLOBJ; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override {
+    return new CPDF_Null;
+  }
 };
 
 class CPDF_Reference : public CPDF_Object {
  public:
   CPDF_Reference(CPDF_IndirectObjectHolder* pDoc, int objnum)
-      : CPDF_Object(REFERENCE), m_pObjList(pDoc), m_RefObjNum(objnum) {}
+      : m_pObjList(pDoc), m_RefObjNum(objnum) {}
+
+  // CPDF_Object.
+  Type GetType() const override { return REFERENCE; }
+  CPDF_Object* Clone(FX_BOOL bDirect = FALSE) const override;
+  CPDF_Object* GetDirect() const override;
+  CFX_ByteString GetString() const override {
+    CPDF_Object* obj = SafeGetDirect();
+    return obj ? obj->GetString() : CFX_ByteString();
+  }
+  CFX_ByteStringC GetConstString() const override {
+    CPDF_Object* obj = SafeGetDirect();
+    return obj ? obj->GetConstString() : CFX_ByteStringC();
+  }
+  FX_FLOAT GetNumber() const override {
+    CPDF_Object* obj = SafeGetDirect();
+    return obj ? obj->GetNumber() : 0;
+  }
+  int GetInteger() const override {
+    CPDF_Object* obj = SafeGetDirect();
+    return obj ? obj->GetInteger() : 0;
+  }
+  CPDF_Dictionary* GetDict() const override {
+    CPDF_Object* obj = SafeGetDirect();
+    return obj ? obj->GetDict() : nullptr;
+  }
+  // TODO(weili): check whether GetUnicodeText() and GetArray() are needed.
+  bool IsReference() const override { return true; }
+  CPDF_Reference* AsReference() override { return this; }
+  const CPDF_Reference* AsReference() const override { return this; }
 
   CPDF_IndirectObjectHolder* GetObjList() const { return m_pObjList; }
-
   FX_DWORD GetRefObjNum() const { return m_RefObjNum; }
 
   void SetRef(CPDF_IndirectObjectHolder* pDoc, FX_DWORD objnum);
 
-  FX_BOOL Identical(CPDF_Reference* pOther) const {
-    return m_RefObjNum == pOther->m_RefObjNum;
+ protected:
+  ~CPDF_Reference() {}
+  CPDF_Object* SafeGetDirect() const {
+    CPDF_Object* obj = GetDirect();
+    if (!obj || obj->IsReference())
+      return nullptr;
+    return obj;
   }
 
- protected:
   CPDF_IndirectObjectHolder* m_pObjList;
-
   FX_DWORD m_RefObjNum;
-  friend class CPDF_Object;
 };
+
 inline CPDF_Reference* ToReference(CPDF_Object* obj) {
   return obj ? obj->AsReference() : nullptr;
 }
+
 inline const CPDF_Reference* ToReference(const CPDF_Object* obj) {
   return obj ? obj->AsReference() : nullptr;
 }
@@ -575,7 +595,7 @@ class CPDF_IndirectObjectHolder {
 
   FX_DWORD GetLastObjNum() const { return m_LastObjNum; }
   iterator begin() { return m_IndirectObjs.begin(); }
-  const_iterator begin() const { return m_IndirectObjs.cbegin(); }
+  const_iterator begin() const { return m_IndirectObjs.begin(); }
   iterator end() { return m_IndirectObjs.end(); }
   const_iterator end() const { return m_IndirectObjs.end(); }
 
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_image.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_image.cpp
index 9296cd6158..3791f5fec0 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_image.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_image.cpp
@@ -49,7 +49,7 @@ CPDF_Image* CPDF_Image::Clone() {
     return m_pDocument->GetPageData()->GetImage(m_pStream);
 
   CPDF_Image* pImage = new CPDF_Image(m_pDocument);
-  pImage->LoadImageF(ToStream(m_pStream->CPDF_Object::Clone()), m_bInline);
+  pImage->LoadImageF(ToStream(m_pStream->Clone()), m_bInline);
   if (m_bInline)
     pImage->SetInlineDict(ToDictionary(m_pInlineDict->Clone(TRUE)));
 
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
index 6b512949ae..813c18a4c5 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
@@ -12,382 +12,38 @@
 #include "core/include/fxcrt/fx_string.h"
 #include "third_party/base/stl_util.h"
 
-namespace {
-
-const FX_DWORD kBlockSize = 1024;
-
-}  // namespace
-
 void CPDF_Object::Release() {
   if (m_ObjNum) {
     return;
   }
   Destroy();
 }
-void CPDF_Object::Destroy() {
-  switch (m_Type) {
-    case STRING:
-      delete AsString();
-      break;
-    case NAME:
-      delete AsName();
-      break;
-    case ARRAY:
-      delete AsArray();
-      break;
-    case DICTIONARY:
-      delete AsDictionary();
-      break;
-    case STREAM:
-      delete AsStream();
-      break;
-    default:
-      delete this;
-  }
-}
-
-const CPDF_Object* CPDF_Object::GetBasicObject() const {
-  const CPDF_Reference* pRef = AsReference();
-  if (!pRef) {
-    // This is not an indirect reference.
-    return this;
-  }
-  if (!pRef->m_pObjList)
-    return nullptr;
-  return pRef->m_pObjList->GetIndirectObject(pRef->GetRefObjNum());
-}
-
-CFX_ByteString CPDF_Object::GetString() const {
-  const CPDF_Object* obj = GetBasicObject();
-  if (obj) {
-    switch (obj->GetType()) {
-      case BOOLEAN:
-        return obj->AsBoolean()->GetString();
-      case NUMBER:
-        return obj->AsNumber()->GetString();
-      case STRING:
-        return obj->AsString()->GetString();
-      case NAME:
-        return obj->AsName()->GetString();
-      default:
-        break;
-    }
-  }
-  return CFX_ByteString();
-}
-
-CFX_ByteStringC CPDF_Object::GetConstString() const {
-  const CPDF_Object* obj = GetBasicObject();
-  if (obj) {
-    FX_DWORD type = obj->GetType();
-    if (type == STRING) {
-      CFX_ByteString str = obj->AsString()->GetString();
-      return CFX_ByteStringC(str);
-    }
-    if (type == NAME) {
-      CFX_ByteString name = obj->AsName()->GetString();
-      return CFX_ByteStringC(name);
-    }
-  }
-  return CFX_ByteStringC();
-}
-
-FX_FLOAT CPDF_Object::GetNumber() const {
-  const CPDF_Object* obj = GetBasicObject();
-  if (obj && obj->GetType() == NUMBER)
-    return obj->AsNumber()->GetNumber();
-  return 0;
-}
-
-FX_FLOAT CPDF_Object::GetNumber16() const {
-  return GetNumber();
-}
-
-int CPDF_Object::GetInteger() const {
-  const CPDF_Object* obj = GetBasicObject();
-  if (obj) {
-    FX_DWORD type = obj->GetType();
-    if (type == BOOLEAN)
-      return obj->AsBoolean()->GetValue();
-    if (type == NUMBER)
-      return obj->AsNumber()->GetInteger();
-  }
-  return 0;
-}
-
-CPDF_Dictionary* CPDF_Object::GetDict() const {
-  const CPDF_Object* obj = GetBasicObject();
-  if (obj) {
-    FX_DWORD type = obj->GetType();
-    if (type == DICTIONARY) {
-      // The method should be made non-const if we want to not be const.
-      // See bug #234.
-      return const_cast<CPDF_Dictionary*>(obj->AsDictionary());
-    }
-    if (type == STREAM)
-      return obj->AsStream()->GetDict();
-  }
-  return nullptr;
-}
-
-CPDF_Array* CPDF_Object::GetArray() const {
-  // The method should be made non-const if we want to not be const.
-  // See bug #234.
-  return const_cast<CPDF_Array*>(AsArray());
-}
-
-void CPDF_Object::SetString(const CFX_ByteString& str) {
-  switch (m_Type) {
-    case BOOLEAN:
-      AsBoolean()->m_bValue = (str == "true");
-      return;
-    case NUMBER:
-      AsNumber()->SetString(str);
-      return;
-    case STRING:
-      AsString()->m_String = str;
-      return;
-    case NAME:
-      AsName()->m_Name = str;
-      return;
-    default:
-      break;
-  }
-  ASSERT(FALSE);
-}
-FX_BOOL CPDF_Object::IsIdentical(CPDF_Object* pOther) const {
-  if (this == pOther)
-    return TRUE;
-  if (!pOther)
-    return FALSE;
-  if (pOther->m_Type != m_Type) {
-    if (IsReference() && GetDirect())
-      return GetDirect()->IsIdentical(pOther);
-    if (pOther->IsReference())
-      return IsIdentical(pOther->GetDirect());
-    return FALSE;
-  }
-  switch (m_Type) {
-    case BOOLEAN:
-      return AsBoolean()->Identical(pOther->AsBoolean());
-    case NUMBER:
-      return AsNumber()->Identical(pOther->AsNumber());
-    case STRING:
-      return AsString()->Identical(pOther->AsString());
-    case NAME:
-      return AsName()->Identical(pOther->AsName());
-    case ARRAY:
-      return AsArray()->Identical(pOther->AsArray());
-    case DICTIONARY:
-      return AsDictionary()->Identical(pOther->AsDictionary());
-    case NULLOBJ:
-      return TRUE;
-    case STREAM:
-      return AsStream()->Identical(pOther->AsStream());
-    case REFERENCE:
-      return AsReference()->Identical(pOther->AsReference());
-  }
-  return FALSE;
-}
-
-CPDF_Object* CPDF_Object::GetDirect() const {
-  const CPDF_Reference* pRef = AsReference();
-  if (!pRef)
-    return const_cast<CPDF_Object*>(this);
-  if (!pRef->m_pObjList)
-    return nullptr;
-  return pRef->m_pObjList->GetIndirectObject(pRef->GetRefObjNum());
-}
-
-CPDF_Object* CPDF_Object::Clone(FX_BOOL bDirect) const {
-  std::set<FX_DWORD> visited;
-  return CloneInternal(bDirect, &visited);
-}
-CPDF_Object* CPDF_Object::CloneInternal(FX_BOOL bDirect,
-                                        std::set<FX_DWORD>* visited) const {
-  switch (m_Type) {
-    case BOOLEAN:
-      return new CPDF_Boolean(AsBoolean()->m_bValue);
-    case NUMBER: {
-      const CPDF_Number* pThis = AsNumber();
-      return new CPDF_Number(pThis->m_bInteger ? pThis->m_Integer
-                                               : pThis->m_Float);
-    }
-    case STRING: {
-      const CPDF_String* pString = AsString();
-      return new CPDF_String(pString->m_String, pString->IsHex());
-    }
-    case NAME:
-      return new CPDF_Name(AsName()->m_Name);
-    case ARRAY: {
-      CPDF_Array* pCopy = new CPDF_Array();
-      const CPDF_Array* pThis = AsArray();
-      int n = pThis->GetCount();
-      for (int i = 0; i < n; i++) {
-        CPDF_Object* value = pThis->m_Objects.GetAt(i);
-        pCopy->m_Objects.Add(value->CloneInternal(bDirect, visited));
-      }
-      return pCopy;
-    }
-    case DICTIONARY: {
-      CPDF_Dictionary* pCopy = new CPDF_Dictionary();
-      const CPDF_Dictionary* pThis = AsDictionary();
-      for (const auto& it : *pThis) {
-        pCopy->m_Map.insert(std::make_pair(
-            it.first, it.second->CloneInternal(bDirect, visited)));
-      }
-      return pCopy;
-    }
-    case NULLOBJ: {
-      return new CPDF_Null;
-    }
-    case STREAM: {
-      const CPDF_Stream* pThis = AsStream();
-      CPDF_StreamAcc acc;
-      acc.LoadAllData(pThis, TRUE);
-      FX_DWORD streamSize = acc.GetSize();
-      CPDF_Dictionary* pDict = pThis->GetDict();
-      if (pDict) {
-        pDict = ToDictionary(pDict->CloneInternal(bDirect, visited));
-      }
-      return new CPDF_Stream(acc.DetachData(), streamSize, pDict);
-    }
-    case REFERENCE: {
-      const CPDF_Reference* pRef = AsReference();
-      FX_DWORD obj_num = pRef->GetRefObjNum();
-      if (bDirect && !pdfium::ContainsKey(*visited, obj_num)) {
-        visited->insert(obj_num);
-        auto* pDirect = pRef->GetDirect();
-        return pDirect ? pDirect->CloneInternal(TRUE, visited) : nullptr;
-      }
-      return new CPDF_Reference(pRef->m_pObjList, obj_num);
-    }
-  }
-  return NULL;
-}
-CPDF_Object* CPDF_Object::CloneRef(CPDF_IndirectObjectHolder* pDoc) const {
-  if (m_ObjNum) {
-    return new CPDF_Reference(pDoc, m_ObjNum);
-  }
-  return Clone();
-}
-CFX_WideString CPDF_Object::GetUnicodeText(CFX_CharMap* pCharMap) const {
-  if (const CPDF_String* pString = AsString())
-    return PDF_DecodeText(pString->m_String, pCharMap);
-
-  if (const CPDF_Stream* pStream = AsStream()) {
-    CPDF_StreamAcc stream;
-    stream.LoadAllData(pStream, FALSE);
-    CFX_WideString result =
-        PDF_DecodeText(stream.GetData(), stream.GetSize(), pCharMap);
-    return result;
-  }
-  if (const CPDF_Name* pName = AsName())
-    return PDF_DecodeText(pName->m_Name, pCharMap);
-  return CFX_WideString();
-}
-void CPDF_Object::SetUnicodeText(const FX_WCHAR* pUnicodes, int len) {
-  if (CPDF_String* pString = AsString()) {
-    pString->m_String = PDF_EncodeText(pUnicodes, len);
-  } else if (CPDF_Stream* pStream = AsStream()) {
-    CFX_ByteString result = PDF_EncodeText(pUnicodes, len);
-    pStream->SetData((uint8_t*)result.c_str(), result.GetLength(), FALSE,
-                     FALSE);
-  }
-}
-
-CPDF_Array* CPDF_Object::AsArray() {
-  return IsArray() ? static_cast<CPDF_Array*>(this) : nullptr;
-}
-
-const CPDF_Array* CPDF_Object::AsArray() const {
-  return IsArray() ? static_cast<const CPDF_Array*>(this) : nullptr;
-}
 
-CPDF_Boolean* CPDF_Object::AsBoolean() {
-  return IsBoolean() ? static_cast<CPDF_Boolean*>(this) : nullptr;
-}
-
-const CPDF_Boolean* CPDF_Object::AsBoolean() const {
-  return IsBoolean() ? static_cast<const CPDF_Boolean*>(this) : nullptr;
-}
-
-CPDF_Dictionary* CPDF_Object::AsDictionary() {
-  return IsDictionary() ? static_cast<CPDF_Dictionary*>(this) : nullptr;
-}
-
-const CPDF_Dictionary* CPDF_Object::AsDictionary() const {
-  return IsDictionary() ? static_cast<const CPDF_Dictionary*>(this) : nullptr;
-}
-
-CPDF_Name* CPDF_Object::AsName() {
-  return IsName() ? static_cast<CPDF_Name*>(this) : nullptr;
-}
-
-const CPDF_Name* CPDF_Object::AsName() const {
-  return IsName() ? static_cast<const CPDF_Name*>(this) : nullptr;
-}
-
-CPDF_Number* CPDF_Object::AsNumber() {
-  return IsNumber() ? static_cast<CPDF_Number*>(this) : nullptr;
-}
-
-const CPDF_Number* CPDF_Object::AsNumber() const {
-  return IsNumber() ? static_cast<const CPDF_Number*>(this) : nullptr;
-}
-
-CPDF_Reference* CPDF_Object::AsReference() {
-  return IsReference() ? static_cast<CPDF_Reference*>(this) : nullptr;
-}
-
-const CPDF_Reference* CPDF_Object::AsReference() const {
-  return IsReference() ? static_cast<const CPDF_Reference*>(this) : nullptr;
+CPDF_Number::CPDF_Number(const CFX_ByteStringC& str) {
+  FX_atonum(str, m_bInteger, &m_Integer);
 }
 
-CPDF_Stream* CPDF_Object::AsStream() {
-  return IsStream() ? static_cast<CPDF_Stream*>(this) : nullptr;
+void CPDF_Number::SetString(const CFX_ByteString& str) {
+  FX_atonum(str, m_bInteger, &m_Integer);
 }
 
-const CPDF_Stream* CPDF_Object::AsStream() const {
-  return IsStream() ? static_cast<const CPDF_Stream*>(this) : nullptr;
+CFX_ByteString CPDF_Number::GetString() const {
+  return m_bInteger ? CFX_ByteString::FormatInteger(m_Integer, FXFORMAT_SIGNED)
+                    : CFX_ByteString::FormatFloat(m_Float);
 }
 
-CPDF_String* CPDF_Object::AsString() {
-  return IsString() ? static_cast<CPDF_String*>(this) : nullptr;
+CPDF_String::CPDF_String(const CFX_WideString& str) : m_bHex(FALSE) {
+  m_String = PDF_EncodeText(str);
 }
 
-const CPDF_String* CPDF_Object::AsString() const {
-  return IsString() ? static_cast<const CPDF_String*>(this) : nullptr;
+CFX_WideString CPDF_String::GetUnicodeText(CFX_CharMap* pCharMap) const {
+  return PDF_DecodeText(m_String, pCharMap);
 }
 
-CPDF_Number::CPDF_Number(int value)
-    : CPDF_Object(NUMBER), m_bInteger(TRUE), m_Integer(value) {}
-
-CPDF_Number::CPDF_Number(FX_FLOAT value)
-    : CPDF_Object(NUMBER), m_bInteger(FALSE), m_Float(value) {}
-
-CPDF_Number::CPDF_Number(const CFX_ByteStringC& str) : CPDF_Object(NUMBER) {
-  FX_atonum(str, m_bInteger, &m_Integer);
+CFX_WideString CPDF_Name::GetUnicodeText(CFX_CharMap* pCharMap) const {
+  return PDF_DecodeText(m_Name, pCharMap);
 }
 
-void CPDF_Number::SetString(const CFX_ByteStringC& str) {
-  FX_atonum(str, m_bInteger, &m_Integer);
-}
-FX_BOOL CPDF_Number::Identical(CPDF_Number* pOther) const {
-  return m_bInteger == pOther->m_bInteger && m_Integer == pOther->m_Integer;
-}
-CFX_ByteString CPDF_Number::GetString() const {
-  return m_bInteger ? CFX_ByteString::FormatInteger(m_Integer, FXFORMAT_SIGNED)
-                    : CFX_ByteString::FormatFloat(m_Float);
-}
-void CPDF_Number::SetNumber(FX_FLOAT value) {
-  m_bInteger = FALSE;
-  m_Float = value;
-}
-CPDF_String::CPDF_String(const CFX_WideString& str)
-    : CPDF_Object(STRING), m_bHex(FALSE) {
-  m_String = PDF_EncodeText(str);
-}
 CPDF_Array::~CPDF_Array() {
   int size = m_Objects.GetSize();
   CPDF_Object** pList = m_Objects.GetData();
@@ -396,6 +52,16 @@ CPDF_Array::~CPDF_Array() {
       pList[i]->Release();
   }
 }
+
+CPDF_Object* CPDF_Array::Clone(FX_BOOL bDirect) const {
+  CPDF_Array* pCopy = new CPDF_Array();
+  for (int i = 0; i < GetCount(); i++) {
+    CPDF_Object* value = m_Objects.GetAt(i);
+    pCopy->m_Objects.Add(value->Clone(bDirect));
+  }
+  return pCopy;
+}
+
 CFX_FloatRect CPDF_Array::GetRect() {
   CFX_FloatRect rect;
   if (!IsArray() || m_Objects.GetSize() != 4)
@@ -407,6 +73,7 @@ CFX_FloatRect CPDF_Array::GetRect() {
   rect.top = GetNumberAt(3);
   return rect;
 }
+
 CFX_Matrix CPDF_Array::GetMatrix() {
   CFX_Matrix matrix;
   if (!IsArray() || m_Objects.GetSize() != 6)
@@ -416,36 +83,43 @@ CFX_Matrix CPDF_Array::GetMatrix() {
              GetNumberAt(4), GetNumberAt(5));
   return matrix;
 }
+
 CPDF_Object* CPDF_Array::GetElement(FX_DWORD i) const {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return nullptr;
   return m_Objects.GetAt(i);
 }
+
 CPDF_Object* CPDF_Array::GetElementValue(FX_DWORD i) const {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return nullptr;
   return m_Objects.GetAt(i)->GetDirect();
 }
+
 CFX_ByteString CPDF_Array::GetStringAt(FX_DWORD i) const {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return CFX_ByteString();
   return m_Objects.GetAt(i)->GetString();
 }
+
 CFX_ByteStringC CPDF_Array::GetConstStringAt(FX_DWORD i) const {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return CFX_ByteStringC();
   return m_Objects.GetAt(i)->GetConstString();
 }
+
 int CPDF_Array::GetIntegerAt(FX_DWORD i) const {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return 0;
   return m_Objects.GetAt(i)->GetInteger();
 }
+
 FX_FLOAT CPDF_Array::GetNumberAt(FX_DWORD i) const {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return 0;
   return m_Objects.GetAt(i)->GetNumber();
 }
+
 CPDF_Dictionary* CPDF_Array::GetDictAt(FX_DWORD i) const {
   CPDF_Object* p = GetElementValue(i);
   if (!p)
@@ -456,12 +130,15 @@ CPDF_Dictionary* CPDF_Array::GetDictAt(FX_DWORD i) const {
     return pStream->GetDict();
   return NULL;
 }
+
 CPDF_Stream* CPDF_Array::GetStreamAt(FX_DWORD i) const {
   return ToStream(GetElementValue(i));
 }
+
 CPDF_Array* CPDF_Array::GetArrayAt(FX_DWORD i) const {
   return ToArray(GetElementValue(i));
 }
+
 void CPDF_Array::RemoveAt(FX_DWORD i, int nCount) {
   if (i >= (FX_DWORD)m_Objects.GetSize())
     return;
@@ -475,6 +152,7 @@ void CPDF_Array::RemoveAt(FX_DWORD i, int nCount) {
   }
   m_Objects.RemoveAt(i, nCount);
 }
+
 void CPDF_Array::SetAt(FX_DWORD i,
                        CPDF_Object* pObj,
                        CPDF_IndirectObjectHolder* pObjs) {
@@ -490,6 +168,7 @@ void CPDF_Array::SetAt(FX_DWORD i,
   }
   m_Objects.SetAt(i, pObj);
 }
+
 void CPDF_Array::InsertAt(FX_DWORD index,
                           CPDF_Object* pObj,
                           CPDF_IndirectObjectHolder* pObjs) {
@@ -499,6 +178,7 @@ void CPDF_Array::InsertAt(FX_DWORD index,
   }
   m_Objects.InsertAt(index, pObj);
 }
+
 void CPDF_Array::Add(CPDF_Object* pObj, CPDF_IndirectObjectHolder* pObjs) {
   if (pObj->GetObjNum()) {
     ASSERT(pObjs);
@@ -506,44 +186,47 @@ void CPDF_Array::Add(CPDF_Object* pObj, CPDF_IndirectObjectHolder* pObjs) {
   }
   m_Objects.Add(pObj);
 }
+
 void CPDF_Array::AddName(const CFX_ByteString& str) {
   ASSERT(IsArray());
   Add(new CPDF_Name(str));
 }
+
 void CPDF_Array::AddString(const CFX_ByteString& str) {
   ASSERT(IsArray());
   Add(new CPDF_String(str, FALSE));
 }
+
 void CPDF_Array::AddInteger(int i) {
   ASSERT(IsArray());
   Add(new CPDF_Number(i));
 }
+
 void CPDF_Array::AddNumber(FX_FLOAT f) {
   ASSERT(IsArray());
-  CPDF_Number* pNumber = new CPDF_Number;
-  pNumber->SetNumber(f);
+  CPDF_Number* pNumber = new CPDF_Number(f);
   Add(pNumber);
 }
+
 void CPDF_Array::AddReference(CPDF_IndirectObjectHolder* pDoc,
                               FX_DWORD objnum) {
   ASSERT(IsArray());
   Add(new CPDF_Reference(pDoc, objnum));
 }
-FX_BOOL CPDF_Array::Identical(CPDF_Array* pOther) const {
-  if (m_Objects.GetSize() != pOther->m_Objects.GetSize()) {
-    return FALSE;
-  }
-  for (int i = 0; i < m_Objects.GetSize(); i++) {
-    if (!m_Objects[i]->IsIdentical(pOther->m_Objects[i]))
-      return FALSE;
-  }
-  return TRUE;
-}
+
 CPDF_Dictionary::~CPDF_Dictionary() {
   for (const auto& it : m_Map) {
     it.second->Release();
   }
 }
+
+CPDF_Object* CPDF_Dictionary::Clone(FX_BOOL bDirect) const {
+  CPDF_Dictionary* pCopy = new CPDF_Dictionary();
+  for (const auto& it : *this)
+    pCopy->m_Map.insert(std::make_pair(it.first, it.second->Clone(bDirect)));
+  return pCopy;
+}
+
 CPDF_Object* CPDF_Dictionary::GetElement(const CFX_ByteStringC& key) const {
   auto it = m_Map.find(key);
   if (it == m_Map.end())
@@ -555,6 +238,7 @@ CPDF_Object* CPDF_Dictionary::GetElementValue(
   CPDF_Object* p = GetElement(key);
   return p ? p->GetDirect() : nullptr;
 }
+
 CFX_ByteString CPDF_Dictionary::GetStringBy(const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElement(key);
   if (p) {
@@ -562,6 +246,7 @@ CFX_ByteString CPDF_Dictionary::GetStringBy(const CFX_ByteStringC& key) const {
   }
   return CFX_ByteString();
 }
+
 CFX_ByteStringC CPDF_Dictionary::GetConstStringBy(
     const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElement(key);
@@ -570,6 +255,7 @@ CFX_ByteStringC CPDF_Dictionary::GetConstStringBy(
   }
   return CFX_ByteStringC();
 }
+
 CFX_WideString CPDF_Dictionary::GetUnicodeTextBy(const CFX_ByteStringC& key,
                                                  CFX_CharMap* pCharMap) const {
   CPDF_Object* p = GetElement(key);
@@ -577,6 +263,7 @@ CFX_WideString CPDF_Dictionary::GetUnicodeTextBy(const CFX_ByteStringC& key,
     p = pRef->GetDirect();
   return p ? p->GetUnicodeText(pCharMap) : CFX_WideString();
 }
+
 CFX_ByteString CPDF_Dictionary::GetStringBy(const CFX_ByteStringC& key,
                                             const CFX_ByteStringC& def) const {
   CPDF_Object* p = GetElement(key);
@@ -585,6 +272,7 @@ CFX_ByteString CPDF_Dictionary::GetStringBy(const CFX_ByteStringC& key,
   }
   return CFX_ByteString(def);
 }
+
 CFX_ByteStringC CPDF_Dictionary::GetConstStringBy(
     const CFX_ByteStringC& key,
     const CFX_ByteStringC& def) const {
@@ -594,6 +282,7 @@ CFX_ByteStringC CPDF_Dictionary::GetConstStringBy(
   }
   return CFX_ByteStringC(def);
 }
+
 int CPDF_Dictionary::GetIntegerBy(const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElement(key);
   if (p) {
@@ -601,6 +290,7 @@ int CPDF_Dictionary::GetIntegerBy(const CFX_ByteStringC& key) const {
   }
   return 0;
 }
+
 int CPDF_Dictionary::GetIntegerBy(const CFX_ByteStringC& key, int def) const {
   CPDF_Object* p = GetElement(key);
   if (p) {
@@ -608,6 +298,7 @@ int CPDF_Dictionary::GetIntegerBy(const CFX_ByteStringC& key, int def) const {
   }
   return def;
 }
+
 FX_FLOAT CPDF_Dictionary::GetNumberBy(const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElement(key);
   if (p) {
@@ -615,6 +306,7 @@ FX_FLOAT CPDF_Dictionary::GetNumberBy(const CFX_ByteStringC& key) const {
   }
   return 0;
 }
+
 FX_BOOL CPDF_Dictionary::GetBooleanBy(const CFX_ByteStringC& key,
                                       FX_BOOL bDefault) const {
   CPDF_Object* p = GetElement(key);
@@ -622,6 +314,7 @@ FX_BOOL CPDF_Dictionary::GetBooleanBy(const CFX_ByteStringC& key,
     return p->GetInteger();
   return bDefault;
 }
+
 CPDF_Dictionary* CPDF_Dictionary::GetDictBy(const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElementValue(key);
   if (!p)
@@ -632,12 +325,15 @@ CPDF_Dictionary* CPDF_Dictionary::GetDictBy(const CFX_ByteStringC& key) const {
     return pStream->GetDict();
   return nullptr;
 }
+
 CPDF_Array* CPDF_Dictionary::GetArrayBy(const CFX_ByteStringC& key) const {
   return ToArray(GetElementValue(key));
 }
+
 CPDF_Stream* CPDF_Dictionary::GetStreamBy(const CFX_ByteStringC& key) const {
   return ToStream(GetElementValue(key));
 }
+
 CFX_FloatRect CPDF_Dictionary::GetRectBy(const CFX_ByteStringC& key) const {
   CFX_FloatRect rect;
   CPDF_Array* pArray = GetArrayBy(key);
@@ -645,6 +341,7 @@ CFX_FloatRect CPDF_Dictionary::GetRectBy(const CFX_ByteStringC& key) const {
     rect = pArray->GetRect();
   return rect;
 }
+
 CFX_Matrix CPDF_Dictionary::GetMatrixBy(const CFX_ByteStringC& key) const {
   CFX_Matrix matrix;
   CPDF_Array* pArray = GetArrayBy(key);
@@ -652,6 +349,7 @@ CFX_Matrix CPDF_Dictionary::GetMatrixBy(const CFX_ByteStringC& key) const {
     matrix = pArray->GetMatrix();
   return matrix;
 }
+
 FX_BOOL CPDF_Dictionary::KeyExist(const CFX_ByteStringC& key) const {
   return pdfium::ContainsKey(m_Map, key);
 }
@@ -677,8 +375,8 @@ void CPDF_Dictionary::SetAt(const CFX_ByteStringC& key, CPDF_Object* pObj) {
   else
     m_Map.erase(it);
 }
+
 void CPDF_Dictionary::RemoveAt(const CFX_ByteStringC& key) {
-  ASSERT(m_Type == DICTIONARY);
   auto it = m_Map.find(key);
   if (it == m_Map.end())
     return;
@@ -686,9 +384,9 @@ void CPDF_Dictionary::RemoveAt(const CFX_ByteStringC& key) {
   it->second->Release();
   m_Map.erase(it);
 }
+
 void CPDF_Dictionary::ReplaceKey(const CFX_ByteStringC& oldkey,
                                  const CFX_ByteStringC& newkey) {
-  ASSERT(m_Type == DICTIONARY);
   auto old_it = m_Map.find(oldkey);
   if (old_it == m_Map.end())
     return;
@@ -707,49 +405,42 @@ void CPDF_Dictionary::ReplaceKey(const CFX_ByteStringC& oldkey,
   }
   m_Map.erase(old_it);
 }
-FX_BOOL CPDF_Dictionary::Identical(CPDF_Dictionary* pOther) const {
-  if (!pOther) {
-    return FALSE;
-  }
-  if (m_Map.size() != pOther->m_Map.size()) {
-    return FALSE;
-  }
-  for (const auto& it : m_Map) {
-    const CFX_ByteString& key = it.first;
-    if (!it.second->IsIdentical(pOther->GetElement(key)))
-      return FALSE;
-  }
-  return TRUE;
-}
+
 void CPDF_Dictionary::SetAtInteger(const CFX_ByteStringC& key, int i) {
   SetAt(key, new CPDF_Number(i));
 }
+
 void CPDF_Dictionary::SetAtName(const CFX_ByteStringC& key,
                                 const CFX_ByteString& name) {
   SetAt(key, new CPDF_Name(name));
 }
+
 void CPDF_Dictionary::SetAtString(const CFX_ByteStringC& key,
                                   const CFX_ByteString& str) {
   SetAt(key, new CPDF_String(str, FALSE));
 }
+
 void CPDF_Dictionary::SetAtReference(const CFX_ByteStringC& key,
                                      CPDF_IndirectObjectHolder* pDoc,
                                      FX_DWORD objnum) {
   SetAt(key, new CPDF_Reference(pDoc, objnum));
 }
+
 void CPDF_Dictionary::AddReference(const CFX_ByteStringC& key,
                                    CPDF_IndirectObjectHolder* pDoc,
                                    FX_DWORD objnum) {
   SetAt(key, new CPDF_Reference(pDoc, objnum));
 }
+
 void CPDF_Dictionary::SetAtNumber(const CFX_ByteStringC& key, FX_FLOAT f) {
-  CPDF_Number* pNumber = new CPDF_Number;
-  pNumber->SetNumber(f);
+  CPDF_Number* pNumber = new CPDF_Number(f);
   SetAt(key, pNumber);
 }
+
 void CPDF_Dictionary::SetAtBoolean(const CFX_ByteStringC& key, FX_BOOL bValue) {
   SetAt(key, new CPDF_Boolean(bValue));
 }
+
 void CPDF_Dictionary::SetAtRect(const CFX_ByteStringC& key,
                                 const CFX_FloatRect& rect) {
   CPDF_Array* pArray = new CPDF_Array;
@@ -759,6 +450,7 @@ void CPDF_Dictionary::SetAtRect(const CFX_ByteStringC& key,
   pArray->AddNumber(rect.top);
   SetAt(key, pArray);
 }
+
 void CPDF_Dictionary::SetAtMatrix(const CFX_ByteStringC& key,
                                   const CFX_Matrix& matrix) {
   CPDF_Array* pArray = new CPDF_Array;
@@ -770,9 +462,9 @@ void CPDF_Dictionary::SetAtMatrix(const CFX_ByteStringC& key,
   pArray->AddNumber(matrix.f);
   SetAt(key, pArray);
 }
+
 CPDF_Stream::CPDF_Stream(uint8_t* pData, FX_DWORD size, CPDF_Dictionary* pDict)
-    : CPDF_Object(STREAM),
-      m_pDict(pDict),
+    : m_pDict(pDict),
       m_dwSize(size),
       m_GenNum(kMemoryBasedGenNum),
       m_pDataBuf(pData) {}
@@ -812,6 +504,18 @@ void CPDF_Stream::InitStream(uint8_t* pData,
     m_pDict->SetAtInteger("Length", size);
   }
 }
+
+CPDF_Object* CPDF_Stream::Clone(FX_BOOL bDirect) const {
+  CPDF_StreamAcc acc;
+  acc.LoadAllData(this, TRUE);
+  FX_DWORD streamSize = acc.GetSize();
+  CPDF_Dictionary* pDict = GetDict();
+  if (pDict) {
+    pDict = ToDictionary(pDict->Clone(bDirect));
+  }
+  return new CPDF_Stream(acc.DetachData(), streamSize, pDict);
+}
+
 void CPDF_Stream::SetData(const uint8_t* pData,
                           FX_DWORD size,
                           FX_BOOL bCompressed,
@@ -821,7 +525,7 @@ void CPDF_Stream::SetData(const uint8_t* pData,
   m_GenNum = kMemoryBasedGenNum;
 
   if (bKeepBuf) {
-    m_pDataBuf = (uint8_t*)pData;
+    m_pDataBuf = const_cast<uint8_t*>(pData);
   } else {
     m_pDataBuf = FX_Alloc(uint8_t, size);
     if (pData) {
@@ -837,6 +541,7 @@ void CPDF_Stream::SetData(const uint8_t* pData,
     m_pDict->RemoveAt("DecodeParms");
   }
 }
+
 FX_BOOL CPDF_Stream::ReadRawData(FX_FILESIZE offset,
                                  uint8_t* buf,
                                  FX_DWORD size) const {
@@ -857,72 +562,10 @@ void CPDF_Stream::InitStreamFromFile(IFX_FileRead* pFile,
   }
 }
 
-FX_BOOL CPDF_Stream::Identical(CPDF_Stream* pOther) const {
-  if (!m_pDict)
-    return !pOther->m_pDict;
-
-  if (!m_pDict->Identical(pOther->m_pDict))
-    return FALSE;
-
-  if (m_dwSize != pOther->m_dwSize)
-    return FALSE;
-
-  if (!IsMemoryBased() && !pOther->IsMemoryBased()) {
-    if (m_pFile == pOther->m_pFile && !m_pFile)
-      return TRUE;
-
-    if (!m_pFile || !pOther->m_pFile)
-      return FALSE;
-
-    uint8_t srcBuf[kBlockSize];
-    uint8_t destBuf[kBlockSize];
-    FX_DWORD size = m_dwSize;
-    if (m_pFile == pOther->m_pFile)
-      return TRUE;
-
-    FX_DWORD offset = 0;
-    while (size > 0) {
-      FX_DWORD actualSize = std::min(size, kBlockSize);
-      m_pFile->ReadBlock(srcBuf, offset, actualSize);
-      pOther->m_pFile->ReadBlock(destBuf, offset, actualSize);
-      if (FXSYS_memcmp(srcBuf, destBuf, actualSize) != 0)
-        return FALSE;
-
-      size -= actualSize;
-      offset += actualSize;
-    }
-    return TRUE;
-  }
-
-  if (!IsMemoryBased() || !pOther->IsMemoryBased()) {
-    IFX_FileRead* pFile = nullptr;
-    uint8_t* pBuf = nullptr;
-    if (!pOther->IsMemoryBased()) {
-      pFile = pOther->m_pFile;
-      pBuf = m_pDataBuf;
-    } else if (!IsMemoryBased()) {
-      pFile = m_pFile;
-      pBuf = pOther->m_pDataBuf;
-    }
-    if (!pBuf)
-      return FALSE;
-
-    uint8_t srcBuf[kBlockSize];
-    FX_DWORD size = m_dwSize;
-    FX_DWORD offset = 0;
-    while (size > 0) {
-      FX_DWORD actualSize = std::min(size, kBlockSize);
-      pFile->ReadBlock(srcBuf, offset, actualSize);
-      if (FXSYS_memcmp(srcBuf, pBuf, actualSize) != 0)
-        return FALSE;
-
-      pBuf += actualSize;
-      size -= actualSize;
-      offset += actualSize;
-    }
-    return TRUE;
-  }
-  return FXSYS_memcmp(m_pDataBuf, pOther->m_pDataBuf, m_dwSize) == 0;
+CFX_WideString CPDF_Stream::GetUnicodeText(CFX_CharMap* pCharMap) const {
+  CPDF_StreamAcc stream;
+  stream.LoadAllData(this, FALSE);
+  return PDF_DecodeText(stream.GetData(), stream.GetSize(), pCharMap);
 }
 
 CPDF_StreamAcc::CPDF_StreamAcc() {
@@ -943,12 +586,12 @@ void CPDF_StreamAcc::LoadAllData(const CPDF_Stream* pStream,
   m_pStream = pStream;
   if (pStream->IsMemoryBased() &&
       (!pStream->GetDict()->KeyExist("Filter") || bRawAccess)) {
-    m_dwSize = pStream->m_dwSize;
-    m_pData = (uint8_t*)pStream->m_pDataBuf;
+    m_dwSize = pStream->GetRawSize();
+    m_pData = pStream->GetRawData();
     return;
   }
   uint8_t* pSrcData;
-  FX_DWORD dwSrcSize = pStream->m_dwSize;
+  FX_DWORD dwSrcSize = pStream->GetRawSize();
   if (dwSrcSize == 0)
     return;
 
@@ -957,7 +600,7 @@ void CPDF_StreamAcc::LoadAllData(const CPDF_Stream* pStream,
     if (!pStream->ReadRawData(0, pSrcData, dwSrcSize))
       return;
   } else {
-    pSrcData = pStream->m_pDataBuf;
+    pSrcData = pStream->GetRawData();
   }
   uint8_t* pDecryptedData = pSrcData;
   FX_DWORD dwDecryptedSize = dwSrcSize;
@@ -973,21 +616,23 @@ void CPDF_StreamAcc::LoadAllData(const CPDF_Stream* pStream,
       m_dwSize = dwDecryptedSize;
     }
   }
-  if (pSrcData != pStream->m_pDataBuf && pSrcData != m_pData) {
+  if (pSrcData != pStream->GetRawData() && pSrcData != m_pData) {
     FX_Free(pSrcData);
   }
   if (pDecryptedData != pSrcData && pDecryptedData != m_pData) {
     FX_Free(pDecryptedData);
   }
   m_pSrcData = NULL;
-  m_bNewBuf = m_pData != pStream->m_pDataBuf;
+  m_bNewBuf = m_pData != pStream->GetRawData();
 }
+
 CPDF_StreamAcc::~CPDF_StreamAcc() {
   if (m_bNewBuf) {
     FX_Free(m_pData);
   }
   FX_Free(m_pSrcData);
 }
+
 const uint8_t* CPDF_StreamAcc::GetData() const {
   if (m_bNewBuf) {
     return m_pData;
@@ -995,8 +640,9 @@ const uint8_t* CPDF_StreamAcc::GetData() const {
   if (!m_pStream) {
     return NULL;
   }
-  return m_pStream->m_pDataBuf;
+  return m_pStream->GetRawData();
 }
+
 FX_DWORD CPDF_StreamAcc::GetSize() const {
   if (m_bNewBuf) {
     return m_dwSize;
@@ -1004,8 +650,9 @@ FX_DWORD CPDF_StreamAcc::GetSize() const {
   if (!m_pStream) {
     return 0;
   }
-  return m_pStream->m_dwSize;
+  return m_pStream->GetRawSize();
 }
+
 uint8_t* CPDF_StreamAcc::DetachData() {
   if (m_bNewBuf) {
     uint8_t* p = m_pData;
@@ -1017,20 +664,36 @@ uint8_t* CPDF_StreamAcc::DetachData() {
   FXSYS_memcpy(p, m_pData, m_dwSize);
   return p;
 }
+
+CPDF_Object* CPDF_Reference::Clone(FX_BOOL bDirect) const {
+  if (bDirect) {
+    auto* pDirect = GetDirect();
+    return pDirect ? pDirect->Clone(TRUE) : nullptr;
+  }
+  return new CPDF_Reference(m_pObjList, m_RefObjNum);
+}
+
 void CPDF_Reference::SetRef(CPDF_IndirectObjectHolder* pDoc, FX_DWORD objnum) {
   m_pObjList = pDoc;
   m_RefObjNum = objnum;
 }
+
+CPDF_Object* CPDF_Reference::GetDirect() const {
+  return m_pObjList ? m_pObjList->GetIndirectObject(m_RefObjNum) : nullptr;
+}
+
 CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder(CPDF_Parser* pParser)
     : m_pParser(pParser), m_LastObjNum(0) {
   if (pParser)
     m_LastObjNum = m_pParser->GetLastObjNum();
 }
+
 CPDF_IndirectObjectHolder::~CPDF_IndirectObjectHolder() {
   for (const auto& pair : m_IndirectObjs) {
     pair.second->Destroy();
   }
 }
+
 CPDF_Object* CPDF_IndirectObjectHolder::GetIndirectObject(FX_DWORD objnum) {
   if (objnum == 0)
     return nullptr;
@@ -1054,6 +717,7 @@ CPDF_Object* CPDF_IndirectObjectHolder::GetIndirectObject(FX_DWORD objnum) {
   m_IndirectObjs[objnum] = pObj;
   return pObj;
 }
+
 FX_DWORD CPDF_IndirectObjectHolder::AddIndirectObject(CPDF_Object* pObj) {
   if (pObj->m_ObjNum) {
     return pObj->m_ObjNum;
@@ -1063,6 +727,7 @@ FX_DWORD CPDF_IndirectObjectHolder::AddIndirectObject(CPDF_Object* pObj) {
   pObj->m_ObjNum = m_LastObjNum;
   return m_LastObjNum;
 }
+
 void CPDF_IndirectObjectHolder::ReleaseIndirectObject(FX_DWORD objnum) {
   auto it = m_IndirectObjs.find(objnum);
   if (it == m_IndirectObjs.end() || it->second->GetObjNum() == -1)
@@ -1070,6 +735,7 @@ void CPDF_IndirectObjectHolder::ReleaseIndirectObject(FX_DWORD objnum) {
   it->second->Destroy();
   m_IndirectObjs.erase(it);
 }
+
 FX_BOOL CPDF_IndirectObjectHolder::InsertIndirectObject(FX_DWORD objnum,
                                                         CPDF_Object* pObj) {
   if (!objnum || !pObj)
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects_unittest.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects_unittest.cpp
index 3965399254..9de31c8673 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects_unittest.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects_unittest.cpp
@@ -26,9 +26,9 @@ class PDFObjectsTest : public testing::Test {
     // Name object.
     CPDF_Name* name_obj = new CPDF_Name("space");
     // Array object.
-    CPDF_Array* array_obj = new CPDF_Array;
-    array_obj->InsertAt(0, new CPDF_Number(8902));
-    array_obj->InsertAt(1, new CPDF_Name("address"));
+    m_ArrayObj = new CPDF_Array;
+    m_ArrayObj->InsertAt(0, new CPDF_Number(8902));
+    m_ArrayObj->InsertAt(1, new CPDF_Name("address"));
     // Dictionary object.
     m_DictObj = new CPDF_Dictionary;
     m_DictObj->SetAt("bool", new CPDF_Boolean(false));
@@ -47,23 +47,92 @@ class PDFObjectsTest : public testing::Test {
     // All direct objects.
     CPDF_Object* objs[] = {boolean_false_obj, boolean_true_obj, number_int_obj,
                            number_float_obj,  str_reg_obj,      str_spec_obj,
-                           name_obj,          array_obj,        m_DictObj,
+                           name_obj,          m_ArrayObj,       m_DictObj,
                            stream_obj,        null_obj};
-    for (int i = 0; i < FX_ArraySize(objs); ++i)
+    m_DirectObjTypes = {
+        CPDF_Object::BOOLEAN, CPDF_Object::BOOLEAN, CPDF_Object::NUMBER,
+        CPDF_Object::NUMBER,  CPDF_Object::STRING,  CPDF_Object::STRING,
+        CPDF_Object::NAME,    CPDF_Object::ARRAY,   CPDF_Object::DICTIONARY,
+        CPDF_Object::STREAM,  CPDF_Object::NULLOBJ};
+    for (size_t i = 0; i < FX_ArraySize(objs); ++i)
       m_DirectObjs.emplace_back(objs[i]);
 
     // Indirect references to indirect objects.
     m_ObjHolder.reset(new CPDF_IndirectObjectHolder(nullptr));
-    CPDF_Object* referred_objs[] = {
-        boolean_true_obj, number_int_obj, str_spec_obj, name_obj,
-        array_obj,        m_DictObj,      stream_obj};
-    for (int i = 0; i < FX_ArraySize(referred_objs); ++i) {
-      m_ObjHolder->AddIndirectObject(referred_objs[i]);
-      m_RefObjs.emplace_back(
-          new CPDF_Reference(m_ObjHolder.get(), referred_objs[i]->GetObjNum()));
+    m_IndirectObjs = {boolean_true_obj, number_int_obj, str_spec_obj, name_obj,
+                      m_ArrayObj,       m_DictObj,      stream_obj};
+    for (size_t i = 0; i < m_IndirectObjs.size(); ++i) {
+      m_ObjHolder->AddIndirectObject(m_IndirectObjs[i]);
+      m_RefObjs.emplace_back(new CPDF_Reference(
+          m_ObjHolder.get(), m_IndirectObjs[i]->GetObjNum()));
     }
   }
 
+  bool Equal(CPDF_Object* obj1, CPDF_Object* obj2) {
+    if (obj1 == obj2)
+      return true;
+    if (!obj1 || !obj2 || obj1->GetType() != obj2->GetType())
+      return false;
+    switch (obj1->GetType()) {
+      case CPDF_Object::BOOLEAN:
+        return obj1->GetInteger() == obj2->GetInteger();
+      case CPDF_Object::NUMBER:
+        return obj1->AsNumber()->IsInteger() == obj2->AsNumber()->IsInteger() &&
+               obj1->GetInteger() == obj2->GetInteger();
+      case CPDF_Object::STRING:
+      case CPDF_Object::NAME:
+        return obj1->GetString() == obj2->GetString();
+      case CPDF_Object::ARRAY: {
+        const CPDF_Array* array1 = obj1->AsArray();
+        const CPDF_Array* array2 = obj2->AsArray();
+        if (array1->GetCount() != array2->GetCount())
+          return false;
+        for (size_t i = 0; i < array1->GetCount(); ++i) {
+          if (!Equal(array1->GetElement(i), array2->GetElement(i)))
+            return false;
+        }
+        return true;
+      }
+      case CPDF_Object::DICTIONARY: {
+        const CPDF_Dictionary* dict1 = obj1->AsDictionary();
+        const CPDF_Dictionary* dict2 = obj2->AsDictionary();
+        if (dict1->GetCount() != dict2->GetCount())
+          return false;
+        for (CPDF_Dictionary::const_iterator it = dict1->begin();
+             it != dict1->end(); ++it) {
+          if (!Equal(it->second, dict2->GetElement(it->first)))
+            return false;
+        }
+        return true;
+      }
+      case CPDF_Object::NULLOBJ:
+        return true;
+      case CPDF_Object::STREAM: {
+        const CPDF_Stream* stream1 = obj1->AsStream();
+        const CPDF_Stream* stream2 = obj2->AsStream();
+        if (!stream1->GetDict() && !stream2->GetDict())
+          return true;
+        // Compare dictionaries.
+        if (!Equal(stream1->GetDict(), stream2->GetDict()))
+          return false;
+        // Compare sizes.
+        if (stream1->GetRawSize() != stream2->GetRawSize())
+          return false;
+        // Compare contents.
+        // Since this function is used for testing Clone(), only memory based
+        // streams need to be handled.
+        if (!stream1->IsMemoryBased() || !stream2->IsMemoryBased())
+          return false;
+        return FXSYS_memcmp(stream1->GetRawData(), stream2->GetRawData(),
+                            stream1->GetRawSize()) == 0;
+      }
+      case CPDF_Object::REFERENCE:
+        return obj1->AsReference()->GetRefObjNum() ==
+               obj2->AsReference()->GetRefObjNum();
+    }
+    return false;
+  }
+
  protected:
   using ScopedObj = std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>>;
 
@@ -71,9 +140,12 @@ class PDFObjectsTest : public testing::Test {
   // refers to some objects in m_DirectObjs.
   std::unique_ptr<CPDF_IndirectObjectHolder> m_ObjHolder;
   std::vector<ScopedObj> m_DirectObjs;
+  std::vector<int> m_DirectObjTypes;
   std::vector<ScopedObj> m_RefObjs;
   CPDF_Dictionary* m_DictObj;
   CPDF_Dictionary* m_StreamDictObj;
+  CPDF_Array* m_ArrayObj;
+  std::vector<CPDF_Object*> m_IndirectObjs;
 };
 
 TEST_F(PDFObjectsTest, GetString) {
@@ -81,13 +153,13 @@ TEST_F(PDFObjectsTest, GetString) {
       "false", "true", "1245", "9.00345", "A simple test", "\t\n", "space",
       "",      "",     "",     ""};
   // Check for direct objects.
-  for (int i = 0; i < m_DirectObjs.size(); ++i)
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
     EXPECT_STREQ(m_DirectObjs[i]->GetString().c_str(), direct_obj_results[i]);
 
   // Check indirect references.
   const char* indirect_obj_results[] = {"true", "1245", "\t\n", "space",
                                         "",     "",     ""};
-  for (int i = 0; i < m_RefObjs.size(); ++i) {
+  for (size_t i = 0; i < m_RefObjs.size(); ++i) {
     EXPECT_STREQ(m_RefObjs[i]->GetString().c_str(), indirect_obj_results[i]);
   }
 }
@@ -97,7 +169,7 @@ TEST_F(PDFObjectsTest, GetConstString) {
       nullptr, nullptr, nullptr, nullptr, "A simple test", "\t\n",
       "space", nullptr, nullptr, nullptr, nullptr};
   // Check for direct objects.
-  for (int i = 0; i < m_DirectObjs.size(); ++i) {
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i) {
     if (!direct_obj_results[i]) {
       EXPECT_EQ(m_DirectObjs[i]->GetConstString().GetCStr(),
                 direct_obj_results[i]);
@@ -109,38 +181,53 @@ TEST_F(PDFObjectsTest, GetConstString) {
   // Check indirect references.
   const char* indirect_obj_results[] = {nullptr, nullptr, "\t\n", "space",
                                         nullptr, nullptr, nullptr};
-  for (int i = 0; i < m_RefObjs.size(); ++i) {
-    if (!indirect_obj_results[i])
+  for (size_t i = 0; i < m_RefObjs.size(); ++i) {
+    if (!indirect_obj_results[i]) {
       EXPECT_EQ(m_RefObjs[i]->GetConstString().GetCStr(), nullptr);
-    else {
+    } else {
       EXPECT_STREQ(m_RefObjs[i]->GetConstString().GetCStr(),
                    indirect_obj_results[i]);
     }
   }
 }
 
+TEST_F(PDFObjectsTest, GetUnicodeText) {
+  const wchar_t* direct_obj_results[] = {
+      L"",     L"",      L"", L"", L"A simple test",
+      L"\t\n", L"space", L"", L"", L"abcdefghijklmnopqrstuvwxyz",
+      L""};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_STREQ(m_DirectObjs[i]->GetUnicodeText().c_str(),
+                 direct_obj_results[i]);
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs)
+    EXPECT_STREQ(it->GetUnicodeText().c_str(), L"");
+}
+
 TEST_F(PDFObjectsTest, GetNumber) {
   const FX_FLOAT direct_obj_results[] = {0, 0, 1245, 9.00345f, 0, 0,
                                          0, 0, 0,    0,        0};
   // Check for direct objects.
-  for (int i = 0; i < m_DirectObjs.size(); ++i)
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
     EXPECT_EQ(m_DirectObjs[i]->GetNumber(), direct_obj_results[i]);
 
   // Check indirect references.
   const FX_FLOAT indirect_obj_results[] = {0, 1245, 0, 0, 0, 0, 0};
-  for (int i = 0; i < m_RefObjs.size(); ++i)
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
     EXPECT_EQ(m_RefObjs[i]->GetNumber(), indirect_obj_results[i]);
 }
 
 TEST_F(PDFObjectsTest, GetInteger) {
   const int direct_obj_results[] = {0, 1, 1245, 9, 0, 0, 0, 0, 0, 0, 0};
   // Check for direct objects.
-  for (int i = 0; i < m_DirectObjs.size(); ++i)
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
     EXPECT_EQ(m_DirectObjs[i]->GetInteger(), direct_obj_results[i]);
 
   // Check indirect references.
   const int indirect_obj_results[] = {1, 1245, 0, 0, 0, 0, 0};
-  for (int i = 0; i < m_RefObjs.size(); ++i)
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
     EXPECT_EQ(m_RefObjs[i]->GetInteger(), indirect_obj_results[i]);
 }
 
@@ -149,12 +236,140 @@ TEST_F(PDFObjectsTest, GetDict) {
       nullptr, nullptr, nullptr,   nullptr,         nullptr, nullptr,
       nullptr, nullptr, m_DictObj, m_StreamDictObj, nullptr};
   // Check for direct objects.
-  for (int i = 0; i < m_DirectObjs.size(); ++i)
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
     EXPECT_EQ(m_DirectObjs[i]->GetDict(), direct_obj_results[i]);
 
   // Check indirect references.
   const CPDF_Dictionary* indirect_obj_results[] = {
       nullptr, nullptr, nullptr, nullptr, nullptr, m_DictObj, m_StreamDictObj};
-  for (int i = 0; i < m_RefObjs.size(); ++i)
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
     EXPECT_EQ(m_RefObjs[i]->GetDict(), indirect_obj_results[i]);
 }
+
+TEST_F(PDFObjectsTest, GetArray) {
+  const CPDF_Array* direct_obj_results[] = {
+      nullptr, nullptr,    nullptr, nullptr, nullptr, nullptr,
+      nullptr, m_ArrayObj, nullptr, nullptr, nullptr};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(m_DirectObjs[i]->GetArray(), direct_obj_results[i]);
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs)
+    EXPECT_EQ(it->GetArray(), nullptr);
+}
+
+TEST_F(PDFObjectsTest, Clone) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i) {
+    ScopedObj obj(m_DirectObjs[i]->Clone());
+    EXPECT_TRUE(Equal(m_DirectObjs[i].get(), obj.get()));
+  }
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs) {
+    ScopedObj obj(it->Clone());
+    EXPECT_TRUE(Equal(it.get(), obj.get()));
+  }
+}
+
+TEST_F(PDFObjectsTest, GetType) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(m_DirectObjs[i]->GetType(), m_DirectObjTypes[i]);
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs)
+    EXPECT_EQ(it->GetType(), CPDF_Object::REFERENCE);
+}
+
+TEST_F(PDFObjectsTest, GetDirect) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(m_DirectObjs[i]->GetDirect(), m_DirectObjs[i].get());
+
+  // Check indirect references.
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
+    EXPECT_EQ(m_RefObjs[i]->GetDirect(), m_IndirectObjs[i]);
+}
+
+TEST_F(PDFObjectsTest, SetString) {
+  // Check for direct objects.
+  const char* const set_values[] = {"true",    "fake", "3.125f", "097",
+                                    "changed", "",     "NewName"};
+  const char* expected[] = {"true",    "false", "3.125",  "97",
+                            "changed", "",      "NewName"};
+  for (size_t i = 0; i < FX_ArraySize(set_values); ++i) {
+    m_DirectObjs[i]->SetString(set_values[i]);
+    EXPECT_STREQ(m_DirectObjs[i]->GetString().c_str(), expected[i]);
+  }
+}
+
+TEST_F(PDFObjectsTest, IsTypeAndAsType) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i) {
+    if (m_DirectObjTypes[i] == CPDF_Object::ARRAY) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsArray());
+      EXPECT_EQ(m_DirectObjs[i]->AsArray(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsArray());
+      EXPECT_EQ(m_DirectObjs[i]->AsArray(), nullptr);
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::BOOLEAN) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsBoolean());
+      EXPECT_EQ(m_DirectObjs[i]->AsBoolean(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsBoolean());
+      EXPECT_EQ(m_DirectObjs[i]->AsBoolean(), nullptr);
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::NAME) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsName());
+      EXPECT_EQ(m_DirectObjs[i]->AsName(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsName());
+      EXPECT_EQ(m_DirectObjs[i]->AsName(), nullptr);
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::NUMBER) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsNumber());
+      EXPECT_EQ(m_DirectObjs[i]->AsNumber(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsNumber());
+      EXPECT_EQ(m_DirectObjs[i]->AsNumber(), nullptr);
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::STRING) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsString());
+      EXPECT_EQ(m_DirectObjs[i]->AsString(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsString());
+      EXPECT_EQ(m_DirectObjs[i]->AsString(), nullptr);
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::DICTIONARY) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsDictionary());
+      EXPECT_EQ(m_DirectObjs[i]->AsDictionary(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsDictionary());
+      EXPECT_EQ(m_DirectObjs[i]->AsDictionary(), nullptr);
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::STREAM) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsStream());
+      EXPECT_EQ(m_DirectObjs[i]->AsStream(), m_DirectObjs[i].get());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsStream());
+      EXPECT_EQ(m_DirectObjs[i]->AsStream(), nullptr);
+    }
+
+    EXPECT_FALSE(m_DirectObjs[i]->IsReference());
+    EXPECT_EQ(m_DirectObjs[i]->AsReference(), nullptr);
+  }
+  // Check indirect references.
+  for (size_t i = 0; i < m_RefObjs.size(); ++i) {
+    EXPECT_TRUE(m_RefObjs[i]->IsReference());
+    EXPECT_EQ(m_RefObjs[i]->AsReference(), m_RefObjs[i].get());
+  }
+}