The final game: mark everything final.

Then revert the ones that break compilation.
Fix one IWYU noticed during presubmit.

Change-Id: I881a8a72818e55dbc4816247e35ff5e3015194e7
Reviewed-on: https://pdfium-review.googlesource.com/41470
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

111 files changed, 136 insertions, 137 deletions

diff --git a/core/fpdfapi/edit/cpdf_creator.cpp b/core/fpdfapi/edit/cpdf_creator.cpp
index 11b0628b01..7af62806da 100644
--- a/core/fpdfapi/edit/cpdf_creator.cpp
+++ b/core/fpdfapi/edit/cpdf_creator.cpp
@@ -28,7 +28,7 @@ namespace {
 
 const size_t kArchiveBufferSize = 32768;
 
-class CFX_FileBufferArchive : public IFX_ArchiveStream {
+class CFX_FileBufferArchive final : public IFX_ArchiveStream {
  public:
   explicit CFX_FileBufferArchive(const RetainPtr<IFX_WriteStream>& archive);
   ~CFX_FileBufferArchive() override;
diff --git a/core/fpdfapi/edit/cpdf_creator_embeddertest.cpp b/core/fpdfapi/edit/cpdf_creator_embeddertest.cpp
index 2d431b8424..1f8f788d34 100644
--- a/core/fpdfapi/edit/cpdf_creator_embeddertest.cpp
+++ b/core/fpdfapi/edit/cpdf_creator_embeddertest.cpp
@@ -20,7 +20,7 @@
 
 namespace {
 
-class FileAccess : public FPDF_FILEACCESS {
+class FileAccess final : public FPDF_FILEACCESS {
  public:
   explicit FileAccess(const std::string& file_name) {
     std::string file_path;
diff --git a/core/fpdfapi/edit/cpdf_stringarchivestream.h b/core/fpdfapi/edit/cpdf_stringarchivestream.h
index bb5481e376..aa744a9ea1 100644
--- a/core/fpdfapi/edit/cpdf_stringarchivestream.h
+++ b/core/fpdfapi/edit/cpdf_stringarchivestream.h
@@ -7,7 +7,7 @@
 
 #include "core/fxcrt/fx_stream.h"
 
-class CPDF_StringArchiveStream : public IFX_ArchiveStream {
+class CPDF_StringArchiveStream final : public IFX_ArchiveStream {
  public:
   explicit CPDF_StringArchiveStream(std::ostringstream* stream);
   ~CPDF_StringArchiveStream() override;
diff --git a/core/fpdfapi/font/cfx_cttgsubtable.h b/core/fpdfapi/font/cfx_cttgsubtable.h
index ff488a5ed7..6b23a8db27 100644
--- a/core/fpdfapi/font/cfx_cttgsubtable.h
+++ b/core/fpdfapi/font/cfx_cttgsubtable.h
@@ -64,14 +64,14 @@ class CFX_CTTGSUBTable {
     uint16_t CoverageFormat;
   };
 
-  struct TCoverageFormat1 : public TCoverageFormatBase {
+  struct TCoverageFormat1 final : public TCoverageFormatBase {
     TCoverageFormat1();
     ~TCoverageFormat1() override;
 
     std::vector<uint16_t> GlyphArray;
   };
 
-  struct TCoverageFormat2 : public TCoverageFormatBase {
+  struct TCoverageFormat2 final : public TCoverageFormatBase {
     TCoverageFormat2();
     ~TCoverageFormat2() override;
 
@@ -94,14 +94,14 @@ class CFX_CTTGSUBTable {
     uint16_t SubstFormat;
   };
 
-  struct TSubTable1 : public TSubTableBase {
+  struct TSubTable1 final : public TSubTableBase {
     TSubTable1();
     ~TSubTable1() override;
 
     int16_t DeltaGlyphID;
   };
 
-  struct TSubTable2 : public TSubTableBase {
+  struct TSubTable2 final : public TSubTableBase {
     TSubTable2();
     ~TSubTable2() override;
 
diff --git a/core/fpdfapi/font/cpdf_cidfont.h b/core/fpdfapi/font/cpdf_cidfont.h
index 9dde95d75e..7aeb54b877 100644
--- a/core/fpdfapi/font/cpdf_cidfont.h
+++ b/core/fpdfapi/font/cpdf_cidfont.h
@@ -32,7 +32,7 @@ class CPDF_CID2UnicodeMap;
 class CPDF_CMap;
 class CPDF_StreamAcc;
 
-class CPDF_CIDFont : public CPDF_Font {
+class CPDF_CIDFont final : public CPDF_Font {
  public:
   CPDF_CIDFont(CPDF_Document* pDocument, CPDF_Dictionary* pFontDict);
   ~CPDF_CIDFont() override;
diff --git a/core/fpdfapi/font/cpdf_cmap.h b/core/fpdfapi/font/cpdf_cmap.h
index 45053bdfb5..228c207876 100644
--- a/core/fpdfapi/font/cpdf_cmap.h
+++ b/core/fpdfapi/font/cpdf_cmap.h
@@ -27,7 +27,7 @@ enum CIDCoding : uint8_t {
   CIDCODING_UTF16,
 };
 
-class CPDF_CMap : public Retainable {
+class CPDF_CMap final : public Retainable {
  public:
   enum CodingScheme : uint8_t {
     OneByte,
diff --git a/core/fpdfapi/font/cpdf_truetypefont.h b/core/fpdfapi/font/cpdf_truetypefont.h
index d63e8f105a..a3066d74fa 100644
--- a/core/fpdfapi/font/cpdf_truetypefont.h
+++ b/core/fpdfapi/font/cpdf_truetypefont.h
@@ -10,7 +10,7 @@
 #include "core/fpdfapi/font/cpdf_simplefont.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPDF_TrueTypeFont : public CPDF_SimpleFont {
+class CPDF_TrueTypeFont final : public CPDF_SimpleFont {
  public:
   CPDF_TrueTypeFont(CPDF_Document* pDocument, CPDF_Dictionary* pFontDict);
   ~CPDF_TrueTypeFont() override;
diff --git a/core/fpdfapi/font/cpdf_type1font.h b/core/fpdfapi/font/cpdf_type1font.h
index cbcb9af3b1..0fdfa807d3 100644
--- a/core/fpdfapi/font/cpdf_type1font.h
+++ b/core/fpdfapi/font/cpdf_type1font.h
@@ -10,7 +10,7 @@
 #include "core/fpdfapi/font/cpdf_simplefont.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPDF_Type1Font : public CPDF_SimpleFont {
+class CPDF_Type1Font final : public CPDF_SimpleFont {
  public:
   CPDF_Type1Font(CPDF_Document* pDocument, CPDF_Dictionary* pFontDict);
   ~CPDF_Type1Font() override;
diff --git a/core/fpdfapi/font/cpdf_type3font.h b/core/fpdfapi/font/cpdf_type3font.h
index 0be1fa3f69..d85bf701df 100644
--- a/core/fpdfapi/font/cpdf_type3font.h
+++ b/core/fpdfapi/font/cpdf_type3font.h
@@ -17,7 +17,7 @@
 class CPDF_Dictionary;
 class CPDF_Type3Char;
 
-class CPDF_Type3Font : public CPDF_SimpleFont {
+class CPDF_Type3Font final : public CPDF_SimpleFont {
  public:
   CPDF_Type3Font(CPDF_Document* pDocument, CPDF_Dictionary* pFontDict);
   ~CPDF_Type3Font() override;
diff --git a/core/fpdfapi/page/cpdf_allstates.h b/core/fpdfapi/page/cpdf_allstates.h
index 730003a96a..e388b9470f 100644
--- a/core/fpdfapi/page/cpdf_allstates.h
+++ b/core/fpdfapi/page/cpdf_allstates.h
@@ -15,7 +15,7 @@ class CPDF_Array;
 class CPDF_Dictionary;
 class CPDF_StreamContentParser;
 
-class CPDF_AllStates : public CPDF_GraphicStates {
+class CPDF_AllStates final : public CPDF_GraphicStates {
  public:
   CPDF_AllStates();
   ~CPDF_AllStates() override;
diff --git a/core/fpdfapi/page/cpdf_clippath.h b/core/fpdfapi/page/cpdf_clippath.h
index 91a25cda1a..c0b5ce5011 100644
--- a/core/fpdfapi/page/cpdf_clippath.h
+++ b/core/fpdfapi/page/cpdf_clippath.h
@@ -44,7 +44,7 @@ class CPDF_ClipPath {
   void Transform(const CFX_Matrix& matrix);
 
  private:
-  class PathData : public Retainable {
+  class PathData final : public Retainable {
    public:
     using PathAndTypeData = std::pair<CPDF_Path, uint8_t>;
 
diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index a3b88b05b8..882b5657d8 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -105,7 +105,7 @@ bool GetWhitePoint(const CPDF_Dictionary* pDict, float* pPoints) {
   return pPoints[0] > 0.0f && pPoints[1] == 1.0f && pPoints[2] > 0.0f;
 }
 
-class CPDF_CalGray : public CPDF_ColorSpace {
+class CPDF_CalGray final : public CPDF_ColorSpace {
  public:
   explicit CPDF_CalGray(CPDF_Document* pDoc);
   ~CPDF_CalGray() override {}
@@ -130,7 +130,7 @@ class CPDF_CalGray : public CPDF_ColorSpace {
   float m_BlackPoint[kBlackWhitePointCount];
 };
 
-class CPDF_CalRGB : public CPDF_ColorSpace {
+class CPDF_CalRGB final : public CPDF_ColorSpace {
  public:
   explicit CPDF_CalRGB(CPDF_Document* pDoc);
   ~CPDF_CalRGB() override {}
@@ -160,7 +160,7 @@ class CPDF_CalRGB : public CPDF_ColorSpace {
   bool m_bMatrix = false;
 };
 
-class CPDF_LabCS : public CPDF_ColorSpace {
+class CPDF_LabCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_LabCS(CPDF_Document* pDoc);
   ~CPDF_LabCS() override {}
@@ -190,7 +190,7 @@ class CPDF_LabCS : public CPDF_ColorSpace {
   float m_Ranges[kRangesCount];
 };
 
-class CPDF_ICCBasedCS : public CPDF_ColorSpace {
+class CPDF_ICCBasedCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_ICCBasedCS(CPDF_Document* pDoc);
   ~CPDF_ICCBasedCS() override;
@@ -226,7 +226,7 @@ class CPDF_ICCBasedCS : public CPDF_ColorSpace {
   std::vector<float> m_pRanges;
 };
 
-class CPDF_IndexedCS : public CPDF_ColorSpace {
+class CPDF_IndexedCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_IndexedCS(CPDF_Document* pDoc);
   ~CPDF_IndexedCS() override;
@@ -248,7 +248,7 @@ class CPDF_IndexedCS : public CPDF_ColorSpace {
   std::vector<float> m_pCompMinMax;
 };
 
-class CPDF_SeparationCS : public CPDF_ColorSpace {
+class CPDF_SeparationCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_SeparationCS(CPDF_Document* pDoc);
   ~CPDF_SeparationCS() override;
@@ -270,7 +270,7 @@ class CPDF_SeparationCS : public CPDF_ColorSpace {
   enum { None, All, Colorant } m_Type;
 };
 
-class CPDF_DeviceNCS : public CPDF_ColorSpace {
+class CPDF_DeviceNCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_DeviceNCS(CPDF_Document* pDoc);
   ~CPDF_DeviceNCS() override;
diff --git a/core/fpdfapi/page/cpdf_colorstate.h b/core/fpdfapi/page/cpdf_colorstate.h
index 49416db1d5..7b72a2a9d2 100644
--- a/core/fpdfapi/page/cpdf_colorstate.h
+++ b/core/fpdfapi/page/cpdf_colorstate.h
@@ -50,7 +50,7 @@ class CPDF_ColorState {
   bool HasRef() const { return !!m_Ref; }
 
  private:
-  class ColorData : public Retainable {
+  class ColorData final : public Retainable {
    public:
     ColorData();
     ColorData(const ColorData& src);
diff --git a/core/fpdfapi/page/cpdf_contentmark.h b/core/fpdfapi/page/cpdf_contentmark.h
index dc4cc08838..1395db12f8 100644
--- a/core/fpdfapi/page/cpdf_contentmark.h
+++ b/core/fpdfapi/page/cpdf_contentmark.h
@@ -40,7 +40,7 @@ class CPDF_ContentMark {
   size_t FindFirstDifference(const CPDF_ContentMark* other) const;
 
  private:
-  class MarkData : public Retainable {
+  class MarkData final : public Retainable {
    public:
     MarkData();
     MarkData(const MarkData& src);
diff --git a/core/fpdfapi/page/cpdf_contentmarkitem.h b/core/fpdfapi/page/cpdf_contentmarkitem.h
index 435aef4b10..a0a92dbc3c 100644
--- a/core/fpdfapi/page/cpdf_contentmarkitem.h
+++ b/core/fpdfapi/page/cpdf_contentmarkitem.h
@@ -17,7 +17,7 @@
 
 class CPDF_Dictionary;
 
-class CPDF_ContentMarkItem : public Retainable {
+class CPDF_ContentMarkItem final : public Retainable {
  public:
   enum ParamType { None, PropertiesDict, DirectDict };
 
diff --git a/core/fpdfapi/page/cpdf_devicecs.h b/core/fpdfapi/page/cpdf_devicecs.h
index bf668c359b..ab88d74c93 100644
--- a/core/fpdfapi/page/cpdf_devicecs.h
+++ b/core/fpdfapi/page/cpdf_devicecs.h
@@ -11,7 +11,7 @@
 
 #include "core/fpdfapi/page/cpdf_colorspace.h"
 
-class CPDF_DeviceCS : public CPDF_ColorSpace {
+class CPDF_DeviceCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_DeviceCS(int family);
   ~CPDF_DeviceCS() override;
diff --git a/core/fpdfapi/page/cpdf_expintfunc.h b/core/fpdfapi/page/cpdf_expintfunc.h
index c93cc86cff..95bdab68e2 100644
--- a/core/fpdfapi/page/cpdf_expintfunc.h
+++ b/core/fpdfapi/page/cpdf_expintfunc.h
@@ -12,7 +12,7 @@
 
 #include "core/fpdfapi/page/cpdf_function.h"
 
-class CPDF_ExpIntFunc : public CPDF_Function {
+class CPDF_ExpIntFunc final : public CPDF_Function {
  public:
   CPDF_ExpIntFunc();
   ~CPDF_ExpIntFunc() override;
diff --git a/core/fpdfapi/page/cpdf_form.h b/core/fpdfapi/page/cpdf_form.h
index 63cc4a96c1..abb5c40a46 100644
--- a/core/fpdfapi/page/cpdf_form.h
+++ b/core/fpdfapi/page/cpdf_form.h
@@ -19,7 +19,7 @@ class CPDF_AllStates;
 class CFX_Matrix;
 class CPDF_Type3Char;
 
-class CPDF_Form : public CPDF_PageObjectHolder {
+class CPDF_Form final : public CPDF_PageObjectHolder {
  public:
   CPDF_Form(CPDF_Document* pDocument,
             CPDF_Dictionary* pPageResources,
diff --git a/core/fpdfapi/page/cpdf_formobject.h b/core/fpdfapi/page/cpdf_formobject.h
index b229dce444..dc53c454c4 100644
--- a/core/fpdfapi/page/cpdf_formobject.h
+++ b/core/fpdfapi/page/cpdf_formobject.h
@@ -14,7 +14,7 @@
 
 class CPDF_Form;
 
-class CPDF_FormObject : public CPDF_PageObject {
+class CPDF_FormObject final : public CPDF_PageObject {
  public:
   CPDF_FormObject(int32_t content_stream,
                   std::unique_ptr<CPDF_Form> pForm,
diff --git a/core/fpdfapi/page/cpdf_generalstate.h b/core/fpdfapi/page/cpdf_generalstate.h
index 4a101b99de..9ee20db8a5 100644
--- a/core/fpdfapi/page/cpdf_generalstate.h
+++ b/core/fpdfapi/page/cpdf_generalstate.h
@@ -77,7 +77,7 @@ class CPDF_GeneralState {
   CFX_Matrix* GetMutableMatrix();
 
  private:
-  class StateData : public Retainable {
+  class StateData final : public Retainable {
    public:
     StateData();
     StateData(const StateData& that);
diff --git a/core/fpdfapi/page/cpdf_iccprofile.h b/core/fpdfapi/page/cpdf_iccprofile.h
index a9e11700f1..0f13b0be21 100644
--- a/core/fpdfapi/page/cpdf_iccprofile.h
+++ b/core/fpdfapi/page/cpdf_iccprofile.h
@@ -16,7 +16,7 @@
 class CLcmsCmm;
 class CPDF_Stream;
 
-class CPDF_IccProfile : public Retainable {
+class CPDF_IccProfile final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfapi/page/cpdf_image.h b/core/fpdfapi/page/cpdf_image.h
index 4306109199..1be9b4d47f 100644
--- a/core/fpdfapi/page/cpdf_image.h
+++ b/core/fpdfapi/page/cpdf_image.h
@@ -22,7 +22,7 @@ class CPDF_Page;
 class PauseIndicatorIface;
 class IFX_SeekableReadStream;
 
-class CPDF_Image : public Retainable {
+class CPDF_Image final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfapi/page/cpdf_imageobject.h b/core/fpdfapi/page/cpdf_imageobject.h
index d54ef8d818..2e01598b8a 100644
--- a/core/fpdfapi/page/cpdf_imageobject.h
+++ b/core/fpdfapi/page/cpdf_imageobject.h
@@ -14,7 +14,7 @@
 
 class CPDF_Image;
 
-class CPDF_ImageObject : public CPDF_PageObject {
+class CPDF_ImageObject final : public CPDF_PageObject {
  public:
   explicit CPDF_ImageObject(int32_t content_stream);
   CPDF_ImageObject();
diff --git a/core/fpdfapi/page/cpdf_page.h b/core/fpdfapi/page/cpdf_page.h
index 44bb6d8798..b641253f84 100644
--- a/core/fpdfapi/page/cpdf_page.h
+++ b/core/fpdfapi/page/cpdf_page.h
@@ -23,7 +23,7 @@ class CPDF_Object;
 class CPDF_PageRenderCache;
 class CPDF_PageRenderContext;
 
-class CPDF_Page : public IPDF_Page, public CPDF_PageObjectHolder {
+class CPDF_Page final : public IPDF_Page, public CPDF_PageObjectHolder {
  public:
   class View {};  // Caller implements as desired, empty here due to layering.
 
diff --git a/core/fpdfapi/page/cpdf_pageobjectlist.h b/core/fpdfapi/page/cpdf_pageobjectlist.h
index 77c7d811e1..1b4bf8f75c 100644
--- a/core/fpdfapi/page/cpdf_pageobjectlist.h
+++ b/core/fpdfapi/page/cpdf_pageobjectlist.h
@@ -12,7 +12,7 @@
 
 class CPDF_PageObject;
 
-class CPDF_PageObjectList
+class CPDF_PageObjectList final
     : public std::deque<std::unique_ptr<CPDF_PageObject>> {
  public:
   CPDF_PageObject* GetPageObjectByIndex(int index) const;
diff --git a/core/fpdfapi/page/cpdf_pathobject.h b/core/fpdfapi/page/cpdf_pathobject.h
index 5155c40c3d..0a1e4d01f9 100644
--- a/core/fpdfapi/page/cpdf_pathobject.h
+++ b/core/fpdfapi/page/cpdf_pathobject.h
@@ -12,7 +12,7 @@
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPDF_PathObject : public CPDF_PageObject {
+class CPDF_PathObject final : public CPDF_PageObject {
  public:
   explicit CPDF_PathObject(int32_t content_stream);
   CPDF_PathObject();
diff --git a/core/fpdfapi/page/cpdf_patterncs.h b/core/fpdfapi/page/cpdf_patterncs.h
index 23735fd8f2..5de9875dbf 100644
--- a/core/fpdfapi/page/cpdf_patterncs.h
+++ b/core/fpdfapi/page/cpdf_patterncs.h
@@ -13,7 +13,7 @@
 
 class CPDF_Document;
 
-class CPDF_PatternCS : public CPDF_ColorSpace {
+class CPDF_PatternCS final : public CPDF_ColorSpace {
  public:
   explicit CPDF_PatternCS(CPDF_Document* pDoc);
   ~CPDF_PatternCS() override;
diff --git a/core/fpdfapi/page/cpdf_psfunc.h b/core/fpdfapi/page/cpdf_psfunc.h
index 1274c21d50..b81c2e7acd 100644
--- a/core/fpdfapi/page/cpdf_psfunc.h
+++ b/core/fpdfapi/page/cpdf_psfunc.h
@@ -14,7 +14,7 @@
 
 class CPDF_Object;
 
-class CPDF_PSFunc : public CPDF_Function {
+class CPDF_PSFunc final : public CPDF_Function {
  public:
   CPDF_PSFunc();
   ~CPDF_PSFunc() override;
diff --git a/core/fpdfapi/page/cpdf_sampledfunc.h b/core/fpdfapi/page/cpdf_sampledfunc.h
index bd129662cf..579fdcea09 100644
--- a/core/fpdfapi/page/cpdf_sampledfunc.h
+++ b/core/fpdfapi/page/cpdf_sampledfunc.h
@@ -14,7 +14,7 @@
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
 #include "core/fxcrt/retain_ptr.h"
 
-class CPDF_SampledFunc : public CPDF_Function {
+class CPDF_SampledFunc final : public CPDF_Function {
  public:
   struct SampleEncodeInfo {
     float encode_max;
diff --git a/core/fpdfapi/page/cpdf_shadingobject.h b/core/fpdfapi/page/cpdf_shadingobject.h
index af88128443..c246870469 100644
--- a/core/fpdfapi/page/cpdf_shadingobject.h
+++ b/core/fpdfapi/page/cpdf_shadingobject.h
@@ -13,7 +13,7 @@
 
 class CPDF_ShadingPattern;
 
-class CPDF_ShadingObject : public CPDF_PageObject {
+class CPDF_ShadingObject final : public CPDF_PageObject {
  public:
   CPDF_ShadingObject(int32_t content_stream,
                      CPDF_ShadingPattern* pattern,
diff --git a/core/fpdfapi/page/cpdf_shadingpattern.h b/core/fpdfapi/page/cpdf_shadingpattern.h
index d7aa1cb272..dbf80874b6 100644
--- a/core/fpdfapi/page/cpdf_shadingpattern.h
+++ b/core/fpdfapi/page/cpdf_shadingpattern.h
@@ -33,7 +33,7 @@ class CPDF_Document;
 class CPDF_Function;
 class CPDF_Object;
 
-class CPDF_ShadingPattern : public CPDF_Pattern {
+class CPDF_ShadingPattern final : public CPDF_Pattern {
  public:
   CPDF_ShadingPattern(CPDF_Document* pDoc,
                       CPDF_Object* pPatternObj,
diff --git a/core/fpdfapi/page/cpdf_stitchfunc.h b/core/fpdfapi/page/cpdf_stitchfunc.h
index 20dac6cbc1..022bd4ee6d 100644
--- a/core/fpdfapi/page/cpdf_stitchfunc.h
+++ b/core/fpdfapi/page/cpdf_stitchfunc.h
@@ -13,7 +13,7 @@
 
 #include "core/fpdfapi/page/cpdf_function.h"
 
-class CPDF_StitchFunc : public CPDF_Function {
+class CPDF_StitchFunc final : public CPDF_Function {
  public:
   CPDF_StitchFunc();
   ~CPDF_StitchFunc() override;
diff --git a/core/fpdfapi/page/cpdf_textobject.h b/core/fpdfapi/page/cpdf_textobject.h
index ac17c6df68..9ed5ff7ff0 100644
--- a/core/fpdfapi/page/cpdf_textobject.h
+++ b/core/fpdfapi/page/cpdf_textobject.h
@@ -23,7 +23,7 @@ class CPDF_TextObjectItem {
   CFX_PointF m_Origin;
 };
 
-class CPDF_TextObject : public CPDF_PageObject {
+class CPDF_TextObject final : public CPDF_PageObject {
  public:
   explicit CPDF_TextObject(int32_t content_stream);
   CPDF_TextObject();
diff --git a/core/fpdfapi/page/cpdf_textstate.h b/core/fpdfapi/page/cpdf_textstate.h
index aa128072b6..c1c3ba8015 100644
--- a/core/fpdfapi/page/cpdf_textstate.h
+++ b/core/fpdfapi/page/cpdf_textstate.h
@@ -59,7 +59,7 @@ class CPDF_TextState {
   float* GetMutableCTM();
 
  private:
-  class TextData : public Retainable {
+  class TextData final : public Retainable {
    public:
     TextData();
     TextData(const TextData& src);
diff --git a/core/fpdfapi/page/cpdf_tilingpattern.h b/core/fpdfapi/page/cpdf_tilingpattern.h
index d9450d7c2f..c79708d635 100644
--- a/core/fpdfapi/page/cpdf_tilingpattern.h
+++ b/core/fpdfapi/page/cpdf_tilingpattern.h
@@ -17,7 +17,7 @@ class CPDF_Document;
 class CPDF_Form;
 class CPDF_Object;
 
-class CPDF_TilingPattern : public CPDF_Pattern {
+class CPDF_TilingPattern final : public CPDF_Pattern {
  public:
   CPDF_TilingPattern(CPDF_Document* pDoc,
                      CPDF_Object* pPatternObj,
diff --git a/core/fpdfapi/parser/cfdf_document.h b/core/fpdfapi/parser/cfdf_document.h
index 6efaa4ce06..6ab751e4dd 100644
--- a/core/fpdfapi/parser/cfdf_document.h
+++ b/core/fpdfapi/parser/cfdf_document.h
@@ -17,7 +17,7 @@
 class CPDF_Dictionary;
 class IFX_SeekableReadStream;
 
-class CFDF_Document : public CPDF_IndirectObjectHolder {
+class CFDF_Document final : public CPDF_IndirectObjectHolder {
  public:
   static std::unique_ptr<CFDF_Document> CreateNewDoc();
   static std::unique_ptr<CFDF_Document> ParseMemory(
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
index 1e63983d51..0c9251ca23 100644
--- a/core/fpdfapi/parser/cpdf_array.h
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -18,7 +18,7 @@
 #include "core/fxcrt/fx_coordinates.h"
 #include "third_party/base/ptr_util.h"
 
-class CPDF_Array : public CPDF_Object {
+class CPDF_Array final : public CPDF_Object {
  public:
   using const_iterator =
       std::vector<std::unique_ptr<CPDF_Object>>::const_iterator;
diff --git a/core/fpdfapi/parser/cpdf_boolean.h b/core/fpdfapi/parser/cpdf_boolean.h
index 61c213bdb9..406381b1b9 100644
--- a/core/fpdfapi/parser/cpdf_boolean.h
+++ b/core/fpdfapi/parser/cpdf_boolean.h
@@ -13,7 +13,7 @@
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPDF_Boolean : public CPDF_Object {
+class CPDF_Boolean final : public CPDF_Object {
  public:
   CPDF_Boolean();
   explicit CPDF_Boolean(bool value);
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
index 5cd0e8be22..4930e5e2e3 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.h
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -21,7 +21,7 @@
 
 class CPDF_IndirectObjectHolder;
 
-class CPDF_Dictionary : public CPDF_Object {
+class CPDF_Dictionary final : public CPDF_Object {
  public:
   using const_iterator =
       std::map<ByteString, std::unique_ptr<CPDF_Object>>::const_iterator;
diff --git a/core/fpdfapi/parser/cpdf_document_unittest.cpp b/core/fpdfapi/parser/cpdf_document_unittest.cpp
index c64da6382a..daaab5de32 100644
--- a/core/fpdfapi/parser/cpdf_document_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_document_unittest.cpp
@@ -47,7 +47,7 @@ std::unique_ptr<CPDF_Dictionary> CreateNumberedPage(size_t number) {
   return page;
 }
 
-class CPDF_TestDocumentForPages : public CPDF_Document {
+class CPDF_TestDocumentForPages final : public CPDF_Document {
  public:
   CPDF_TestDocumentForPages() : CPDF_Document() {
     // Set up test
@@ -99,7 +99,7 @@ class CPDF_TestDocumentForPages : public CPDF_Document {
   }
 };
 
-class CPDF_TestDocumentWithPageWithoutPageNum : public CPDF_Document {
+class CPDF_TestDocumentWithPageWithoutPageNum final : public CPDF_Document {
  public:
   CPDF_TestDocumentWithPageWithoutPageNum() : CPDF_Document() {
     // Set up test
@@ -124,13 +124,13 @@ class CPDF_TestDocumentWithPageWithoutPageNum : public CPDF_Document {
   const CPDF_Object* inlined_page_;
 };
 
-class TestLinearized : public CPDF_LinearizedHeader {
+class TestLinearized final : public CPDF_LinearizedHeader {
  public:
   explicit TestLinearized(CPDF_Dictionary* dict)
       : CPDF_LinearizedHeader(dict, 0) {}
 };
 
-class CPDF_TestDocPagesWithoutKids : public CPDF_Document {
+class CPDF_TestDocPagesWithoutKids final : public CPDF_Document {
  public:
   CPDF_TestDocPagesWithoutKids() : CPDF_Document() {
     CPDF_Dictionary* pagesDict = NewIndirect<CPDF_Dictionary>();
@@ -143,7 +143,7 @@ class CPDF_TestDocPagesWithoutKids : public CPDF_Document {
   }
 };
 
-class CPDF_TestDocumentAllowSetParser : public CPDF_Document {
+class CPDF_TestDocumentAllowSetParser final : public CPDF_Document {
  public:
   using CPDF_Document::SetParser;
 };
diff --git a/core/fpdfapi/parser/cpdf_hint_tables_unittest.cpp b/core/fpdfapi/parser/cpdf_hint_tables_unittest.cpp
index c372d74a00..c3b05acbc4 100644
--- a/core/fpdfapi/parser/cpdf_hint_tables_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_hint_tables_unittest.cpp
@@ -40,7 +40,7 @@ std::unique_ptr<CPDF_DataAvail> MakeDataAvailFromFile(
       nullptr, MakeValidatorFromFile(file_name), true);
 }
 
-class TestLinearizedHeader : public CPDF_LinearizedHeader {
+class TestLinearizedHeader final : public CPDF_LinearizedHeader {
  public:
   TestLinearizedHeader(const CPDF_Dictionary* pDict,
                        FX_FILESIZE szLastXRefOffset)
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder_unittest.cpp b/core/fpdfapi/parser/cpdf_indirect_object_holder_unittest.cpp
index 666264f50b..6f913ca01b 100644
--- a/core/fpdfapi/parser/cpdf_indirect_object_holder_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder_unittest.cpp
@@ -14,7 +14,7 @@
 
 namespace {
 
-class MockIndirectObjectHolder : public CPDF_IndirectObjectHolder {
+class MockIndirectObjectHolder final : public CPDF_IndirectObjectHolder {
  public:
   MockIndirectObjectHolder() {}
   ~MockIndirectObjectHolder() override {}
diff --git a/core/fpdfapi/parser/cpdf_name.h b/core/fpdfapi/parser/cpdf_name.h
index eef6bca715..1ef6c64c59 100644
--- a/core/fpdfapi/parser/cpdf_name.h
+++ b/core/fpdfapi/parser/cpdf_name.h
@@ -13,7 +13,7 @@
 #include "core/fxcrt/string_pool_template.h"
 #include "core/fxcrt/weak_ptr.h"
 
-class CPDF_Name : public CPDF_Object {
+class CPDF_Name final : public CPDF_Object {
  public:
   CPDF_Name(WeakPtr<ByteStringPool> pPool, const ByteString& str);
   ~CPDF_Name() override;
diff --git a/core/fpdfapi/parser/cpdf_null.h b/core/fpdfapi/parser/cpdf_null.h
index 003ad2feee..c72d3b02d5 100644
--- a/core/fpdfapi/parser/cpdf_null.h
+++ b/core/fpdfapi/parser/cpdf_null.h
@@ -11,7 +11,7 @@
 
 #include "core/fpdfapi/parser/cpdf_object.h"
 
-class CPDF_Null : public CPDF_Object {
+class CPDF_Null final : public CPDF_Object {
  public:
   CPDF_Null();
 
diff --git a/core/fpdfapi/parser/cpdf_number.h b/core/fpdfapi/parser/cpdf_number.h
index 4681bb216a..b5faf82bb2 100644
--- a/core/fpdfapi/parser/cpdf_number.h
+++ b/core/fpdfapi/parser/cpdf_number.h
@@ -13,7 +13,7 @@
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPDF_Number : public CPDF_Object {
+class CPDF_Number final : public CPDF_Object {
  public:
   CPDF_Number();
   explicit CPDF_Number(int value);
diff --git a/core/fpdfapi/parser/cpdf_object_avail_unittest.cpp b/core/fpdfapi/parser/cpdf_object_avail_unittest.cpp
index 5c3da70530..e2b23d44f4 100644
--- a/core/fpdfapi/parser/cpdf_object_avail_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_object_avail_unittest.cpp
@@ -20,7 +20,7 @@
 
 namespace {
 
-class TestReadValidator : public CPDF_ReadValidator {
+class TestReadValidator final : public CPDF_ReadValidator {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
@@ -35,7 +35,7 @@ class TestReadValidator : public CPDF_ReadValidator {
   ~TestReadValidator() override {}
 };
 
-class TestHolder : public CPDF_IndirectObjectHolder {
+class TestHolder final : public CPDF_IndirectObjectHolder {
  public:
   enum class ObjectState {
     Unavailable,
@@ -93,7 +93,7 @@ class TestHolder : public CPDF_IndirectObjectHolder {
   RetainPtr<TestReadValidator> validator_;
 };
 
-class CPDF_ObjectAvailFailOnExclude : public CPDF_ObjectAvail {
+class CPDF_ObjectAvailFailOnExclude final : public CPDF_ObjectAvail {
  public:
   using CPDF_ObjectAvail::CPDF_ObjectAvail;
   ~CPDF_ObjectAvailFailOnExclude() override {}
@@ -103,7 +103,7 @@ class CPDF_ObjectAvailFailOnExclude : public CPDF_ObjectAvail {
   }
 };
 
-class CPDF_ObjectAvailExcludeArray : public CPDF_ObjectAvail {
+class CPDF_ObjectAvailExcludeArray final : public CPDF_ObjectAvail {
  public:
   using CPDF_ObjectAvail::CPDF_ObjectAvail;
   ~CPDF_ObjectAvailExcludeArray() override {}
@@ -112,7 +112,7 @@ class CPDF_ObjectAvailExcludeArray : public CPDF_ObjectAvail {
   }
 };
 
-class CPDF_ObjectAvailExcludeTypeKey : public CPDF_ObjectAvail {
+class CPDF_ObjectAvailExcludeTypeKey final : public CPDF_ObjectAvail {
  public:
   using CPDF_ObjectAvail::CPDF_ObjectAvail;
   ~CPDF_ObjectAvailExcludeTypeKey() override {}
diff --git a/core/fpdfapi/parser/cpdf_object_walker.cpp b/core/fpdfapi/parser/cpdf_object_walker.cpp
index 8424c0fc89..91638662c3 100644
--- a/core/fpdfapi/parser/cpdf_object_walker.cpp
+++ b/core/fpdfapi/parser/cpdf_object_walker.cpp
@@ -12,7 +12,7 @@
 
 namespace {
 
-class StreamIterator : public CPDF_ObjectWalker::SubobjectIterator {
+class StreamIterator final : public CPDF_ObjectWalker::SubobjectIterator {
  public:
   explicit StreamIterator(const CPDF_Stream* stream)
       : SubobjectIterator(stream) {}
@@ -33,7 +33,7 @@ class StreamIterator : public CPDF_ObjectWalker::SubobjectIterator {
   bool is_finished_ = false;
 };
 
-class DictionaryIterator : public CPDF_ObjectWalker::SubobjectIterator {
+class DictionaryIterator final : public CPDF_ObjectWalker::SubobjectIterator {
  public:
   explicit DictionaryIterator(const CPDF_Dictionary* dictionary)
       : SubobjectIterator(dictionary) {}
@@ -64,7 +64,7 @@ class DictionaryIterator : public CPDF_ObjectWalker::SubobjectIterator {
   ByteString dict_key_;
 };
 
-class ArrayIterator : public CPDF_ObjectWalker::SubobjectIterator {
+class ArrayIterator final : public CPDF_ObjectWalker::SubobjectIterator {
  public:
   explicit ArrayIterator(const CPDF_Array* array) : SubobjectIterator(array) {}
 
diff --git a/core/fpdfapi/parser/cpdf_object_walker.h b/core/fpdfapi/parser/cpdf_object_walker.h
index 57506b9545..e0fd35de29 100644
--- a/core/fpdfapi/parser/cpdf_object_walker.h
+++ b/core/fpdfapi/parser/cpdf_object_walker.h
@@ -55,7 +55,7 @@ class CPDF_ObjectWalker {
   std::stack<std::unique_ptr<SubobjectIterator>> stack_;
 };
 
-class CPDF_NonConstObjectWalker : public CPDF_ObjectWalker {
+class CPDF_NonConstObjectWalker final : public CPDF_ObjectWalker {
  public:
   explicit CPDF_NonConstObjectWalker(CPDF_Object* root)
       : CPDF_ObjectWalker(root) {}
diff --git a/core/fpdfapi/parser/cpdf_page_object_avail.h b/core/fpdfapi/parser/cpdf_page_object_avail.h
index 8c740ed045..b62ca4c33a 100644
--- a/core/fpdfapi/parser/cpdf_page_object_avail.h
+++ b/core/fpdfapi/parser/cpdf_page_object_avail.h
@@ -9,7 +9,7 @@
 
 // Helper for check availability of page's object tree.
 // Exclude references to pages.
-class CPDF_PageObjectAvail : public CPDF_ObjectAvail {
+class CPDF_PageObjectAvail final : public CPDF_ObjectAvail {
  public:
   using CPDF_ObjectAvail::CPDF_ObjectAvail;
   ~CPDF_PageObjectAvail() override;
diff --git a/core/fpdfapi/parser/cpdf_page_object_avail_unittest.cpp b/core/fpdfapi/parser/cpdf_page_object_avail_unittest.cpp
index 14ba0e3273..f278b6e57c 100644
--- a/core/fpdfapi/parser/cpdf_page_object_avail_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_page_object_avail_unittest.cpp
@@ -21,8 +21,7 @@
 
 namespace {
 
-
-class TestReadValidator : public CPDF_ReadValidator {
+class TestReadValidator final : public CPDF_ReadValidator {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
@@ -37,7 +36,7 @@ class TestReadValidator : public CPDF_ReadValidator {
   ~TestReadValidator() override {}
 };
 
-class TestHolder : public CPDF_IndirectObjectHolder {
+class TestHolder final : public CPDF_IndirectObjectHolder {
  public:
   enum class ObjectState {
     Unavailable,
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index 029851570a..32629bc873 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -47,7 +47,7 @@ uint32_t GetVarInt(const uint8_t* p, int32_t n) {
   return result;
 }
 
-class ObjectsHolderStub : public CPDF_Parser::ParsedObjectsHolder {
+class ObjectsHolderStub final : public CPDF_Parser::ParsedObjectsHolder {
  public:
   ObjectsHolderStub() = default;
   ~ObjectsHolderStub() override = default;
diff --git a/core/fpdfapi/parser/cpdf_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_parser_unittest.cpp
index 00f3770e87..28c907a101 100644
--- a/core/fpdfapi/parser/cpdf_parser_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_parser_unittest.cpp
@@ -29,7 +29,7 @@ CPDF_CrossRefTable::ObjectInfo GetObjInfo(const CPDF_Parser& parser,
 }  // namespace
 
 // A wrapper class to help test member functions of CPDF_Parser.
-class CPDF_TestParser : public CPDF_Parser {
+class CPDF_TestParser final : public CPDF_Parser {
  public:
   CPDF_TestParser() {}
   ~CPDF_TestParser() {}
diff --git a/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp b/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp
index 640269884d..cf8b9b65a1 100644
--- a/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp
@@ -20,7 +20,7 @@ std::pair<FX_FILESIZE, FX_FILESIZE> MakeRange(uint32_t start, uint32_t end) {
   return std::pair<FX_FILESIZE, FX_FILESIZE>(start, end);
 }
 
-class MockFileAvail : public CPDF_DataAvail::FileAvail {
+class MockFileAvail final : public CPDF_DataAvail::FileAvail {
  public:
   MockFileAvail() : available_range_(0, 0) {}
   ~MockFileAvail() override {}
@@ -42,7 +42,7 @@ class MockFileAvail : public CPDF_DataAvail::FileAvail {
   std::pair<FX_FILESIZE, FX_FILESIZE> available_range_;
 };
 
-class MockDownloadHints : public CPDF_DataAvail::DownloadHints {
+class MockDownloadHints final : public CPDF_DataAvail::DownloadHints {
  public:
   MockDownloadHints() : last_requested_range_(0, 0) {}
   ~MockDownloadHints() override {}
diff --git a/core/fpdfapi/parser/cpdf_reference.h b/core/fpdfapi/parser/cpdf_reference.h
index cdb5d5e674..cb9c6ed1d4 100644
--- a/core/fpdfapi/parser/cpdf_reference.h
+++ b/core/fpdfapi/parser/cpdf_reference.h
@@ -15,7 +15,7 @@
 
 class CPDF_IndirectObjectHolder;
 
-class CPDF_Reference : public CPDF_Object {
+class CPDF_Reference final : public CPDF_Object {
  public:
   CPDF_Reference(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum);
   ~CPDF_Reference() override;
diff --git a/core/fpdfapi/parser/cpdf_stream.h b/core/fpdfapi/parser/cpdf_stream.h
index 3deb9cddec..9d8cf6d896 100644
--- a/core/fpdfapi/parser/cpdf_stream.h
+++ b/core/fpdfapi/parser/cpdf_stream.h
@@ -15,7 +15,7 @@
 #include "core/fpdfapi/parser/cpdf_object.h"
 #include "core/fxcrt/fx_stream.h"
 
-class CPDF_Stream : public CPDF_Object {
+class CPDF_Stream final : public CPDF_Object {
  public:
   CPDF_Stream();
   CPDF_Stream(std::unique_ptr<uint8_t, FxFreeDeleter> pData,
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.h b/core/fpdfapi/parser/cpdf_stream_acc.h
index 5d18723df5..fae8ba0516 100644
--- a/core/fpdfapi/parser/cpdf_stream_acc.h
+++ b/core/fpdfapi/parser/cpdf_stream_acc.h
@@ -16,7 +16,7 @@
 #include "core/fxcrt/retain_ptr.h"
 #include "third_party/base/span.h"
 
-class CPDF_StreamAcc : public Retainable {
+class CPDF_StreamAcc final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfapi/parser/cpdf_stream_acc_unittest.cpp b/core/fpdfapi/parser/cpdf_stream_acc_unittest.cpp
index dcebf0b3a7..1fbb342548 100644
--- a/core/fpdfapi/parser/cpdf_stream_acc_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_stream_acc_unittest.cpp
@@ -12,7 +12,7 @@
 
 namespace {
 
-class InvalidStream : public IFX_SeekableReadStream {
+class InvalidStream final : public IFX_SeekableReadStream {
  public:
   InvalidStream() = default;
   ~InvalidStream() override = default;
diff --git a/core/fpdfapi/parser/cpdf_string.h b/core/fpdfapi/parser/cpdf_string.h
index 144fe64cba..75cc3c4fe1 100644
--- a/core/fpdfapi/parser/cpdf_string.h
+++ b/core/fpdfapi/parser/cpdf_string.h
@@ -15,7 +15,7 @@
 #include "core/fxcrt/string_pool_template.h"
 #include "core/fxcrt/weak_ptr.h"
 
-class CPDF_String : public CPDF_Object {
+class CPDF_String final : public CPDF_Object {
  public:
   CPDF_String();
   CPDF_String(WeakPtr<ByteStringPool> pPool, const ByteString& str, bool bHex);
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.cpp b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
index 65a8d78b13..bba96d9b34 100644
--- a/core/fpdfapi/parser/cpdf_syntax_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
@@ -34,7 +34,7 @@ namespace {
 
 enum class ReadStatus { Normal, Backslash, Octal, FinishOctal, CarriageReturn };
 
-class ReadableSubStream : public IFX_SeekableReadStream {
+class ReadableSubStream final : public IFX_SeekableReadStream {
  public:
   ReadableSubStream(const RetainPtr<IFX_SeekableReadStream>& pFileRead,
                     FX_FILESIZE part_offset,
diff --git a/core/fpdfapi/render/cpdf_dibbase.h b/core/fpdfapi/render/cpdf_dibbase.h
index a1008470b6..423069db25 100644
--- a/core/fpdfapi/render/cpdf_dibbase.h
+++ b/core/fpdfapi/render/cpdf_dibbase.h
@@ -39,7 +39,7 @@ struct DIB_COMP_DATA {
 
 #define FPDF_HUGE_IMAGE_SIZE 60000000
 
-class CPDF_DIBBase : public CFX_DIBBase {
+class CPDF_DIBBase final : public CFX_DIBBase {
  public:
   enum class LoadState : uint8_t { kFail, kSuccess, kContinue };
 
diff --git a/core/fpdfapi/render/cpdf_dibtransferfunc.h b/core/fpdfapi/render/cpdf_dibtransferfunc.h
index 61abd2e23c..62e0157665 100644
--- a/core/fpdfapi/render/cpdf_dibtransferfunc.h
+++ b/core/fpdfapi/render/cpdf_dibtransferfunc.h
@@ -15,7 +15,7 @@
 
 class CPDF_TransferFunc;
 
-class CPDF_DIBTransferFunc : public CFX_FilteredDIB {
+class CPDF_DIBTransferFunc final : public CFX_FilteredDIB {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfapi/render/cpdf_transferfunc.h b/core/fpdfapi/render/cpdf_transferfunc.h
index e8964727c6..d45184eb92 100644
--- a/core/fpdfapi/render/cpdf_transferfunc.h
+++ b/core/fpdfapi/render/cpdf_transferfunc.h
@@ -14,7 +14,7 @@
 class CPDF_Document;
 class CFX_DIBBase;
 
-class CPDF_TransferFunc : public Retainable {
+class CPDF_TransferFunc final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfapi/render/cpdf_type3cache.h b/core/fpdfapi/render/cpdf_type3cache.h
index f0bfbd63b6..de802c589b 100644
--- a/core/fpdfapi/render/cpdf_type3cache.h
+++ b/core/fpdfapi/render/cpdf_type3cache.h
@@ -18,7 +18,7 @@
 
 class CPDF_Type3Glyphs;
 
-class CPDF_Type3Cache : public Retainable {
+class CPDF_Type3Cache final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfdoc/cpdf_occontext.h b/core/fpdfdoc/cpdf_occontext.h
index 67763610f4..16b28ba06f 100644
--- a/core/fpdfdoc/cpdf_occontext.h
+++ b/core/fpdfdoc/cpdf_occontext.h
@@ -17,7 +17,7 @@ class CPDF_Dictionary;
 class CPDF_Document;
 class CPDF_PageObject;
 
-class CPDF_OCContext : public Retainable {
+class CPDF_OCContext final : public Retainable {
  public:
   enum UsageType { View = 0, Design, Print, Export };
 
diff --git a/core/fpdfdoc/cpdf_structelement.h b/core/fpdfdoc/cpdf_structelement.h
index 79e8dd92c8..355599ff87 100644
--- a/core/fpdfdoc/cpdf_structelement.h
+++ b/core/fpdfdoc/cpdf_structelement.h
@@ -34,7 +34,7 @@ class CPDF_StructKid {
   uint32_t m_ContentId;   // For PageContent, StreamContent.
 };
 
-class CPDF_StructElement : public Retainable {
+class CPDF_StructElement final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fpdfdoc/cpvt_floatrect.h b/core/fpdfdoc/cpvt_floatrect.h
index c5eb2202bb..4dca3aaa43 100644
--- a/core/fpdfdoc/cpvt_floatrect.h
+++ b/core/fpdfdoc/cpvt_floatrect.h
@@ -9,7 +9,7 @@
 
 #include "core/fxcrt/fx_coordinates.h"
 
-class CPVT_FloatRect : public CFX_FloatRect {
+class CPVT_FloatRect final : public CFX_FloatRect {
  public:
   CPVT_FloatRect() { left = top = right = bottom = 0.0f; }
 
diff --git a/core/fpdfdoc/cpvt_fontmap.h b/core/fpdfdoc/cpvt_fontmap.h
index f1a27753ac..6d8ca062c1 100644
--- a/core/fpdfdoc/cpvt_fontmap.h
+++ b/core/fpdfdoc/cpvt_fontmap.h
@@ -17,7 +17,7 @@ class CPDF_Document;
 class CPDF_Dictionary;
 class CPDF_Font;
 
-class CPVT_FontMap : public IPVT_FontMap {
+class CPVT_FontMap final : public IPVT_FontMap {
  public:
   CPVT_FontMap(CPDF_Document* pDoc,
                CPDF_Dictionary* pResDict,
diff --git a/core/fpdftext/cpdf_linkextract_unittest.cpp b/core/fpdftext/cpdf_linkextract_unittest.cpp
index 30438e6c10..f4bd197dda 100644
--- a/core/fpdftext/cpdf_linkextract_unittest.cpp
+++ b/core/fpdftext/cpdf_linkextract_unittest.cpp
@@ -7,7 +7,7 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 // Class to help test functions in CPDF_LinkExtract class.
-class CPDF_TestLinkExtract : public CPDF_LinkExtract {
+class CPDF_TestLinkExtract final : public CPDF_LinkExtract {
  public:
   CPDF_TestLinkExtract() : CPDF_LinkExtract(nullptr) {}
 
diff --git a/core/fxcodec/bmp/cfx_bmpcontext.h b/core/fxcodec/bmp/cfx_bmpcontext.h
index 198d080fb8..89e6463872 100644
--- a/core/fxcodec/bmp/cfx_bmpcontext.h
+++ b/core/fxcodec/bmp/cfx_bmpcontext.h
@@ -10,7 +10,7 @@
 #include "core/fxcodec/bmp/cfx_bmpdecompressor.h"
 #include "core/fxcodec/bmp/fx_bmp.h"
 
-class CFX_BmpContext : public CCodec_BmpModule::Context {
+class CFX_BmpContext final : public CCodec_BmpModule::Context {
  public:
   CFX_BmpContext(CCodec_BmpModule* pModule,
                  CCodec_BmpModule::Delegate* pDelegate);
diff --git a/core/fxcodec/codec/ccodec_pngmodule.cpp b/core/fxcodec/codec/ccodec_pngmodule.cpp
index 98db4e272e..2c22f6bdba 100644
--- a/core/fxcodec/codec/ccodec_pngmodule.cpp
+++ b/core/fxcodec/codec/ccodec_pngmodule.cpp
@@ -23,7 +23,7 @@
 
 #define PNG_ERROR_SIZE 256
 
-class CPngContext : public CCodec_PngModule::Context {
+class CPngContext final : public CCodec_PngModule::Context {
  public:
   CPngContext(CCodec_PngModule* pModule, CCodec_PngModule::Delegate* pDelegate);
   ~CPngContext() override;
diff --git a/core/fxcodec/codec/ccodec_tiffmodule.cpp b/core/fxcodec/codec/ccodec_tiffmodule.cpp
index 5f74b28cdc..78f631cba9 100644
--- a/core/fxcodec/codec/ccodec_tiffmodule.cpp
+++ b/core/fxcodec/codec/ccodec_tiffmodule.cpp
@@ -32,7 +32,7 @@ struct TiffDeleter {
 
 }  // namespace
 
-class CTiffContext : public CCodec_TiffModule::Context {
+class CTiffContext final : public CCodec_TiffModule::Context {
  public:
   CTiffContext() = default;
   ~CTiffContext() override = default;
diff --git a/core/fxcodec/codec/cfx_codec_memory.h b/core/fxcodec/codec/cfx_codec_memory.h
index e726dc5320..2907e892d2 100644
--- a/core/fxcodec/codec/cfx_codec_memory.h
+++ b/core/fxcodec/codec/cfx_codec_memory.h
@@ -8,7 +8,7 @@
 #include "core/fxcrt/retain_ptr.h"
 #include "third_party/base/span.h"
 
-class CFX_CodecMemory : public Retainable {
+class CFX_CodecMemory final : public Retainable {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fxcodec/codec/fx_codec.cpp b/core/fxcodec/codec/fx_codec.cpp
index 54245a5b99..053aa71da2 100644
--- a/core/fxcodec/codec/fx_codec.cpp
+++ b/core/fxcodec/codec/fx_codec.cpp
@@ -1517,7 +1517,7 @@ CFX_DIBAttribute::~CFX_DIBAttribute() {
 }
 #endif  // PDF_ENABLE_XFA
 
-class CCodec_RLScanlineDecoder : public CCodec_ScanlineDecoder {
+class CCodec_RLScanlineDecoder final : public CCodec_ScanlineDecoder {
  public:
   CCodec_RLScanlineDecoder();
   ~CCodec_RLScanlineDecoder() override;
diff --git a/core/fxcodec/codec/fx_codec_fax.cpp b/core/fxcodec/codec/fx_codec_fax.cpp
index aabc110010..c6e71b6b60 100644
--- a/core/fxcodec/codec/fx_codec_fax.cpp
+++ b/core/fxcodec/codec/fx_codec_fax.cpp
@@ -447,7 +447,7 @@ void FaxGet1DLine(const uint8_t* src_buf,
 
 }  // namespace
 
-class CCodec_FaxDecoder : public CCodec_ScanlineDecoder {
+class CCodec_FaxDecoder final : public CCodec_ScanlineDecoder {
  public:
   CCodec_FaxDecoder(const uint8_t* src_buf,
                     uint32_t src_size,
diff --git a/core/fxcodec/codec/fx_codec_flate.cpp b/core/fxcodec/codec/fx_codec_flate.cpp
index 39d27a4955..11bdf67c42 100644
--- a/core/fxcodec/codec/fx_codec_flate.cpp
+++ b/core/fxcodec/codec/fx_codec_flate.cpp
@@ -623,7 +623,7 @@ uint32_t CCodec_FlateScanlineDecoder::GetSrcOffset() {
   return FlateGetPossiblyTruncatedTotalIn(m_pFlate.get());
 }
 
-class CCodec_FlatePredictorScanlineDecoder
+class CCodec_FlatePredictorScanlineDecoder final
     : public CCodec_FlateScanlineDecoder {
  public:
   CCodec_FlatePredictorScanlineDecoder(const uint8_t* src_buf,
diff --git a/core/fxcodec/codec/fx_codec_jpeg.cpp b/core/fxcodec/codec/fx_codec_jpeg.cpp
index 4c37465386..d8e94b0285 100644
--- a/core/fxcodec/codec/fx_codec_jpeg.cpp
+++ b/core/fxcodec/codec/fx_codec_jpeg.cpp
@@ -29,7 +29,7 @@ extern "C" {
 #endif
 }  // extern "C"
 
-class CJpegContext : public CCodec_JpegModule::Context {
+class CJpegContext final : public CCodec_JpegModule::Context {
  public:
   CJpegContext();
   ~CJpegContext() override;
@@ -162,7 +162,7 @@ static bool JpegLoadInfo(const uint8_t* src_buf,
   return true;
 }
 
-class CCodec_JpegDecoder : public CCodec_ScanlineDecoder {
+class CCodec_JpegDecoder final : public CCodec_ScanlineDecoder {
  public:
   CCodec_JpegDecoder();
   ~CCodec_JpegDecoder() override;
diff --git a/core/fxcodec/gif/cfx_gifcontext_unittest.cpp b/core/fxcodec/gif/cfx_gifcontext_unittest.cpp
index 0d8941f72f..25f12b2724 100644
--- a/core/fxcodec/gif/cfx_gifcontext_unittest.cpp
+++ b/core/fxcodec/gif/cfx_gifcontext_unittest.cpp
@@ -7,7 +7,7 @@
 #include "core/fxcrt/unowned_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-class CFX_GifContextForTest : public CFX_GifContext {
+class CFX_GifContextForTest final : public CFX_GifContext {
  public:
   CFX_GifContextForTest(CCodec_GifModule* gif_module,
                         CCodec_GifModule::Delegate* delegate)
diff --git a/core/fxcrt/cfx_fileaccess_posix.h b/core/fxcrt/cfx_fileaccess_posix.h
index 381f115a13..7b8230de18 100644
--- a/core/fxcrt/cfx_fileaccess_posix.h
+++ b/core/fxcrt/cfx_fileaccess_posix.h
@@ -16,7 +16,7 @@
 #error "Included on the wrong platform"
 #endif
 
-class CFX_FileAccess_Posix : public FileAccessIface {
+class CFX_FileAccess_Posix final : public FileAccessIface {
  public:
   CFX_FileAccess_Posix();
   ~CFX_FileAccess_Posix() override;
diff --git a/core/fxcrt/cfx_fileaccess_windows.h b/core/fxcrt/cfx_fileaccess_windows.h
index 4352a2b521..fad2ed6f94 100644
--- a/core/fxcrt/cfx_fileaccess_windows.h
+++ b/core/fxcrt/cfx_fileaccess_windows.h
@@ -14,7 +14,7 @@
 #error "Included on the wrong platform"
 #endif
 
-class CFX_FileAccess_Windows : public FileAccessIface {
+class CFX_FileAccess_Windows final : public FileAccessIface {
  public:
   CFX_FileAccess_Windows();
   ~CFX_FileAccess_Windows() override;
diff --git a/core/fxcrt/cfx_memorystream.h b/core/fxcrt/cfx_memorystream.h
index 99e39a8ef3..c09c39011b 100644
--- a/core/fxcrt/cfx_memorystream.h
+++ b/core/fxcrt/cfx_memorystream.h
@@ -13,7 +13,7 @@
 #include "core/fxcrt/fx_stream.h"
 #include "core/fxcrt/retain_ptr.h"
 
-class CFX_MemoryStream : public IFX_SeekableStream {
+class CFX_MemoryStream final : public IFX_SeekableStream {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fxcrt/cfx_seekablemultistream.h b/core/fxcrt/cfx_seekablemultistream.h
index 4bd26b9863..ac15386b99 100644
--- a/core/fxcrt/cfx_seekablemultistream.h
+++ b/core/fxcrt/cfx_seekablemultistream.h
@@ -15,7 +15,7 @@
 class CPDF_Stream;
 class CPDF_StreamAcc;
 
-class CFX_SeekableMultiStream : public IFX_SeekableStream {
+class CFX_SeekableMultiStream final : public IFX_SeekableStream {
  public:
   explicit CFX_SeekableMultiStream(
       const std::vector<const CPDF_Stream*>& streams);
diff --git a/core/fxcrt/cfx_seekablestreamproxy.h b/core/fxcrt/cfx_seekablestreamproxy.h
index 9b6b3a11c9..b193b1801a 100644
--- a/core/fxcrt/cfx_seekablestreamproxy.h
+++ b/core/fxcrt/cfx_seekablestreamproxy.h
@@ -13,7 +13,7 @@
 #include "core/fxcrt/fx_system.h"
 #include "core/fxcrt/retain_ptr.h"
 
-class CFX_SeekableStreamProxy : public IFX_SeekableReadStream {
+class CFX_SeekableStreamProxy final : public IFX_SeekableReadStream {
  public:
   enum class From {
     Begin = 0,
diff --git a/core/fxcrt/cfx_widetextbuf.h b/core/fxcrt/cfx_widetextbuf.h
index 84553a3e59..483f75d318 100644
--- a/core/fxcrt/cfx_widetextbuf.h
+++ b/core/fxcrt/cfx_widetextbuf.h
@@ -11,7 +11,7 @@
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 
-class CFX_WideTextBuf : public CFX_BinaryBuf {
+class CFX_WideTextBuf final : public CFX_BinaryBuf {
  public:
   void AppendChar(wchar_t wch);
   size_t GetLength() const override;
diff --git a/core/fxcrt/css/cfx_csscolorvalue.h b/core/fxcrt/css/cfx_csscolorvalue.h
index f59c0c5d3d..0156caa786 100644
--- a/core/fxcrt/css/cfx_csscolorvalue.h
+++ b/core/fxcrt/css/cfx_csscolorvalue.h
@@ -9,7 +9,7 @@
 
 #include "core/fxcrt/css/cfx_cssvalue.h"
 
-class CFX_CSSColorValue : public CFX_CSSValue {
+class CFX_CSSColorValue final : public CFX_CSSValue {
  public:
   explicit CFX_CSSColorValue(FX_ARGB color);
   ~CFX_CSSColorValue() override;
diff --git a/core/fxcrt/css/cfx_csscomputedstyle.h b/core/fxcrt/css/cfx_csscomputedstyle.h
index 5080a7a3c2..f97f3f1d7d 100644
--- a/core/fxcrt/css/cfx_csscomputedstyle.h
+++ b/core/fxcrt/css/cfx_csscomputedstyle.h
@@ -15,7 +15,7 @@
 
 class CFX_CSSValueList;
 
-class CFX_CSSComputedStyle : public Retainable {
+class CFX_CSSComputedStyle final : public Retainable {
  public:
   class InheritedData {
    public:
diff --git a/core/fxcrt/css/cfx_cssenumvalue.h b/core/fxcrt/css/cfx_cssenumvalue.h
index 0d6b87e85d..c397761d5a 100644
--- a/core/fxcrt/css/cfx_cssenumvalue.h
+++ b/core/fxcrt/css/cfx_cssenumvalue.h
@@ -9,7 +9,7 @@
 
 #include "core/fxcrt/css/cfx_cssvalue.h"
 
-class CFX_CSSEnumValue : public CFX_CSSValue {
+class CFX_CSSEnumValue final : public CFX_CSSValue {
  public:
   explicit CFX_CSSEnumValue(CFX_CSSPropertyValue value);
   ~CFX_CSSEnumValue() override;
diff --git a/core/fxcrt/css/cfx_cssnumbervalue.h b/core/fxcrt/css/cfx_cssnumbervalue.h
index a49328d663..a977750f08 100644
--- a/core/fxcrt/css/cfx_cssnumbervalue.h
+++ b/core/fxcrt/css/cfx_cssnumbervalue.h
@@ -23,7 +23,7 @@ enum class CFX_CSSNumberType {
   Picas,
 };
 
-class CFX_CSSNumberValue : public CFX_CSSValue {
+class CFX_CSSNumberValue final : public CFX_CSSValue {
  public:
   CFX_CSSNumberValue(CFX_CSSNumberType type, float value);
   ~CFX_CSSNumberValue() override;
diff --git a/core/fxcrt/css/cfx_cssstringvalue.h b/core/fxcrt/css/cfx_cssstringvalue.h
index d72078a630..d49393c305 100644
--- a/core/fxcrt/css/cfx_cssstringvalue.h
+++ b/core/fxcrt/css/cfx_cssstringvalue.h
@@ -9,7 +9,7 @@
 
 #include "core/fxcrt/css/cfx_cssvalue.h"
 
-class CFX_CSSStringValue : public CFX_CSSValue {
+class CFX_CSSStringValue final : public CFX_CSSValue {
  public:
   explicit CFX_CSSStringValue(const WideString& value);
   ~CFX_CSSStringValue() override;
diff --git a/core/fxcrt/css/cfx_cssvaluelist.h b/core/fxcrt/css/cfx_cssvaluelist.h
index d2b0c6e7d1..5e04c649b9 100644
--- a/core/fxcrt/css/cfx_cssvaluelist.h
+++ b/core/fxcrt/css/cfx_cssvaluelist.h
@@ -11,7 +11,7 @@
 
 #include "core/fxcrt/css/cfx_cssvalue.h"
 
-class CFX_CSSValueList : public CFX_CSSValue {
+class CFX_CSSValueList final : public CFX_CSSValue {
  public:
   explicit CFX_CSSValueList(std::vector<RetainPtr<CFX_CSSValue>>& list);
   ~CFX_CSSValueList() override;
diff --git a/core/fxcrt/fx_coordinates.h b/core/fxcrt/fx_coordinates.h
index f84c5ee220..05e60c47b5 100644
--- a/core/fxcrt/fx_coordinates.h
+++ b/core/fxcrt/fx_coordinates.h
@@ -132,7 +132,7 @@ using CFX_Size = CFX_STemplate<int32_t>;
 using CFX_SizeF = CFX_STemplate<float>;
 
 template <class BaseType>
-class CFX_VTemplate : public CFX_PTemplate<BaseType> {
+class CFX_VTemplate final : public CFX_PTemplate<BaseType> {
  public:
   using CFX_PTemplate<BaseType>::x;
   using CFX_PTemplate<BaseType>::y;
diff --git a/core/fxcrt/observable_unittest.cpp b/core/fxcrt/observable_unittest.cpp
index 63e61b8513..5c55805afb 100644
--- a/core/fxcrt/observable_unittest.cpp
+++ b/core/fxcrt/observable_unittest.cpp
@@ -12,7 +12,7 @@
 namespace fxcrt {
 namespace {
 
-class PseudoObservable : public Observable<PseudoObservable> {
+class PseudoObservable final : public Observable<PseudoObservable> {
  public:
   PseudoObservable() {}
   int SomeMethod() { return 42; }
diff --git a/core/fxcrt/shared_copy_on_write_unittest.cpp b/core/fxcrt/shared_copy_on_write_unittest.cpp
index 57e33d1019..6764c69300 100644
--- a/core/fxcrt/shared_copy_on_write_unittest.cpp
+++ b/core/fxcrt/shared_copy_on_write_unittest.cpp
@@ -29,7 +29,7 @@ class Observer {
   std::map<std::string, int> destruction_counts_;
 };
 
-class Object : public Retainable {
+class Object final : public Retainable {
  public:
   Object(Observer* observer, const std::string& name)
       : name_(name), observer_(observer) {
diff --git a/core/fxcrt/xml/cfx_xmlchardata.h b/core/fxcrt/xml/cfx_xmlchardata.h
index 9e5669a464..71e9407ca2 100644
--- a/core/fxcrt/xml/cfx_xmlchardata.h
+++ b/core/fxcrt/xml/cfx_xmlchardata.h
@@ -14,7 +14,7 @@
 
 class CFX_XMLDocument;
 
-class CFX_XMLCharData : public CFX_XMLText {
+class CFX_XMLCharData final : public CFX_XMLText {
  public:
   explicit CFX_XMLCharData(const WideString& wsCData);
   ~CFX_XMLCharData() override;
diff --git a/core/fxcrt/xml/cfx_xmlelement.h b/core/fxcrt/xml/cfx_xmlelement.h
index 394866042c..f54587c4e4 100644
--- a/core/fxcrt/xml/cfx_xmlelement.h
+++ b/core/fxcrt/xml/cfx_xmlelement.h
@@ -16,7 +16,7 @@
 
 class CFX_XMLDocument;
 
-class CFX_XMLElement : public CFX_XMLNode {
+class CFX_XMLElement final : public CFX_XMLNode {
  public:
   explicit CFX_XMLElement(const WideString& wsTag);
   ~CFX_XMLElement() override;
diff --git a/core/fxcrt/xml/cfx_xmlinstruction.h b/core/fxcrt/xml/cfx_xmlinstruction.h
index 8962d73ac1..18f84c3c3d 100644
--- a/core/fxcrt/xml/cfx_xmlinstruction.h
+++ b/core/fxcrt/xml/cfx_xmlinstruction.h
@@ -15,7 +15,7 @@
 
 class CFX_XMLDocument;
 
-class CFX_XMLInstruction : public CFX_XMLNode {
+class CFX_XMLInstruction final : public CFX_XMLNode {
  public:
   explicit CFX_XMLInstruction(const WideString& wsTarget);
   ~CFX_XMLInstruction() override;
diff --git a/core/fxge/agg/fx_agg_driver.h b/core/fxge/agg/fx_agg_driver.h
index 167b211746..6d6b988c3a 100644
--- a/core/fxge/agg/fx_agg_driver.h
+++ b/core/fxge/agg/fx_agg_driver.h
@@ -30,7 +30,7 @@ class CAgg_PathData {
   agg::path_storage m_PathData;
 };
 
-class CFX_AggDeviceDriver : public RenderDeviceDriverIface {
+class CFX_AggDeviceDriver final : public RenderDeviceDriverIface {
  public:
   CFX_AggDeviceDriver(const RetainPtr<CFX_DIBitmap>& pBitmap,
                       bool bRgbByteOrder,
diff --git a/core/fxge/android/cfx_androidfontinfo.h b/core/fxge/android/cfx_androidfontinfo.h
index 62ad7184fe..f671bfbbb7 100644
--- a/core/fxge/android/cfx_androidfontinfo.h
+++ b/core/fxge/android/cfx_androidfontinfo.h
@@ -14,7 +14,7 @@
 
 class CFPF_SkiaFontMgr;
 
-class CFX_AndroidFontInfo : public SystemFontInfoIface {
+class CFX_AndroidFontInfo final : public SystemFontInfoIface {
  public:
   CFX_AndroidFontInfo();
   ~CFX_AndroidFontInfo() override;
diff --git a/core/fxge/apple/fx_mac_imp.cpp b/core/fxge/apple/fx_mac_imp.cpp
index f4a62a62d8..62ac33c51b 100644
--- a/core/fxge/apple/fx_mac_imp.cpp
+++ b/core/fxge/apple/fx_mac_imp.cpp
@@ -35,7 +35,7 @@ const struct {
     {"Times-Italic", "Times New Roman Italic"},
 };
 
-class CFX_MacFontInfo : public CFX_FolderFontInfo {
+class CFX_MacFontInfo final : public CFX_FolderFontInfo {
  public:
   CFX_MacFontInfo() {}
   ~CFX_MacFontInfo() override {}
diff --git a/core/fxge/cfx_defaultrenderdevice.h b/core/fxge/cfx_defaultrenderdevice.h
index 07e3cc57c9..937088f2b2 100644
--- a/core/fxge/cfx_defaultrenderdevice.h
+++ b/core/fxge/cfx_defaultrenderdevice.h
@@ -12,7 +12,7 @@
 
 class SkPictureRecorder;
 
-class CFX_DefaultRenderDevice : public CFX_RenderDevice {
+class CFX_DefaultRenderDevice final : public CFX_RenderDevice {
  public:
   CFX_DefaultRenderDevice();
   ~CFX_DefaultRenderDevice() override;
diff --git a/core/fxge/cfx_graphstatedata.h b/core/fxge/cfx_graphstatedata.h
index 1afff83c1c..a907f2a922 100644
--- a/core/fxge/cfx_graphstatedata.h
+++ b/core/fxge/cfx_graphstatedata.h
@@ -10,7 +10,7 @@
 #include "core/fxcrt/fx_system.h"
 #include "core/fxcrt/retain_ptr.h"
 
-class CFX_GraphStateData : public Retainable {
+class CFX_GraphStateData final : public Retainable {
  public:
   enum LineCap { LineCapButt = 0, LineCapRound = 1, LineCapSquare = 2 };
 
diff --git a/core/fxge/cfx_pathdata.h b/core/fxge/cfx_pathdata.h
index 5c2be627bf..9d96407de9 100644
--- a/core/fxge/cfx_pathdata.h
+++ b/core/fxge/cfx_pathdata.h
@@ -29,7 +29,7 @@ class FX_PATHPOINT {
   bool m_CloseFigure;
 };
 
-class CFX_PathData : public Retainable {
+class CFX_PathData final : public Retainable {
  public:
   CFX_PathData();
   CFX_PathData(const CFX_PathData& src);
diff --git a/core/fxge/cfx_unicodeencodingex.h b/core/fxge/cfx_unicodeencodingex.h
index 5632d9665d..d9d349a88b 100644
--- a/core/fxge/cfx_unicodeencodingex.h
+++ b/core/fxge/cfx_unicodeencodingex.h
@@ -15,7 +15,7 @@
 #include "core/fxge/cfx_unicodeencoding.h"
 #include "core/fxge/fx_dib.h"
 
-class CFX_UnicodeEncodingEx : public CFX_UnicodeEncoding {
+class CFX_UnicodeEncodingEx final : public CFX_UnicodeEncoding {
  public:
   CFX_UnicodeEncodingEx(CFX_Font* pFont, uint32_t EncodingID);
   ~CFX_UnicodeEncodingEx() override;
diff --git a/core/fxge/cfx_windowsrenderdevice.h b/core/fxge/cfx_windowsrenderdevice.h
index 9701ca5186..4470a74c45 100644
--- a/core/fxge/cfx_windowsrenderdevice.h
+++ b/core/fxge/cfx_windowsrenderdevice.h
@@ -36,7 +36,7 @@ extern PDFiumEnsureTypefaceCharactersAccessible
 #endif
 extern WindowsPrintMode g_pdfium_print_mode;
 
-class CFX_WindowsRenderDevice : public CFX_RenderDevice {
+class CFX_WindowsRenderDevice final : public CFX_RenderDevice {
  public:
   static RenderDeviceDriverIface* CreateDriver(HDC hDC);
 
diff --git a/core/fxge/dib/cfx_bitmapcomposer.h b/core/fxge/dib/cfx_bitmapcomposer.h
index f1bf0e9f32..50a53dbc2b 100644
--- a/core/fxge/dib/cfx_bitmapcomposer.h
+++ b/core/fxge/dib/cfx_bitmapcomposer.h
@@ -18,7 +18,7 @@
 class CFX_ClipRgn;
 class CFX_DIBitmap;
 
-class CFX_BitmapComposer : public ScanlineComposerIface {
+class CFX_BitmapComposer final : public ScanlineComposerIface {
  public:
   CFX_BitmapComposer();
   ~CFX_BitmapComposer() override;
diff --git a/core/fxge/dib/cfx_bitmapstorer.h b/core/fxge/dib/cfx_bitmapstorer.h
index 7d3482fc3f..3da1f70487 100644
--- a/core/fxge/dib/cfx_bitmapstorer.h
+++ b/core/fxge/dib/cfx_bitmapstorer.h
@@ -16,7 +16,7 @@
 #include "core/fxge/dib/scanlinecomposer_iface.h"
 #include "third_party/base/stl_util.h"
 
-class CFX_BitmapStorer : public ScanlineComposerIface {
+class CFX_BitmapStorer final : public ScanlineComposerIface {
  public:
   CFX_BitmapStorer();
   ~CFX_BitmapStorer() override;
diff --git a/core/fxge/dib/cfx_imagetransformer.cpp b/core/fxge/dib/cfx_imagetransformer.cpp
index 0042462c89..66446ce52c 100644
--- a/core/fxge/dib/cfx_imagetransformer.cpp
+++ b/core/fxge/dib/cfx_imagetransformer.cpp
@@ -180,7 +180,7 @@ class CPDF_FixedMatrix {
   const int f;
 };
 
-class CFX_BilinearMatrix : public CPDF_FixedMatrix {
+class CFX_BilinearMatrix final : public CPDF_FixedMatrix {
  public:
   explicit CFX_BilinearMatrix(const CFX_Matrix& src) : CPDF_FixedMatrix(src) {}
 
diff --git a/core/fxge/fx_ge_linux.cpp b/core/fxge/fx_ge_linux.cpp
index d2da781881..4d4f4e625e 100644
--- a/core/fxge/fx_ge_linux.cpp
+++ b/core/fxge/fx_ge_linux.cpp
@@ -66,7 +66,7 @@ size_t GetJapanesePreference(const char* facearr,
   return 2;
 }
 
-class CFX_LinuxFontInfo : public CFX_FolderFontInfo {
+class CFX_LinuxFontInfo final : public CFX_FolderFontInfo {
  public:
   CFX_LinuxFontInfo() {}
   ~CFX_LinuxFontInfo() override {}
diff --git a/core/fxge/skia/fx_skia_device.h b/core/fxge/skia/fx_skia_device.h
index ce6ca6b000..4baeacbce5 100644
--- a/core/fxge/skia/fx_skia_device.h
+++ b/core/fxge/skia/fx_skia_device.h
@@ -22,7 +22,7 @@ class SkPictureRecorder;
 class SkiaState;
 struct SkIRect;
 
-class CFX_SkiaDeviceDriver : public RenderDeviceDriverIface {
+class CFX_SkiaDeviceDriver final : public RenderDeviceDriverIface {
  public:
   CFX_SkiaDeviceDriver(const RetainPtr<CFX_DIBitmap>& pBitmap,
                        bool bRgbByteOrder,
diff --git a/core/fxge/win32/cfx_windowsdib.h b/core/fxge/win32/cfx_windowsdib.h
index c64fc7dc16..4b7de7d5f9 100644
--- a/core/fxge/win32/cfx_windowsdib.h
+++ b/core/fxge/win32/cfx_windowsdib.h
@@ -24,7 +24,7 @@ struct WINDIB_Open_Args_ {
   const wchar_t* path_name;
 };
 
-class CFX_WindowsDIB : public CFX_DIBitmap {
+class CFX_WindowsDIB final : public CFX_DIBitmap {
  public:
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
diff --git a/core/fxge/win32/cpsoutput.h b/core/fxge/win32/cpsoutput.h
index 49317a64a5..04e5ac1fa0 100644
--- a/core/fxge/win32/cpsoutput.h
+++ b/core/fxge/win32/cpsoutput.h
@@ -12,7 +12,7 @@
 #include "core/fxcrt/fx_stream.h"
 #include "core/fxcrt/fx_system.h"
 
-class CPSOutput : public IFX_WriteStream {
+class CPSOutput final : public IFX_WriteStream {
  public:
   enum class OutputMode { kExtEscape, kGdiComment };
 
diff --git a/core/fxge/win32/win32_int.h b/core/fxge/win32/win32_int.h
index 76a1d8800e..0bc68c46b9 100644
--- a/core/fxge/win32/win32_int.h
+++ b/core/fxge/win32/win32_int.h
@@ -188,7 +188,7 @@ class CGdiDeviceDriver : public RenderDeviceDriverIface {
   int m_RenderCaps;
 };
 
-class CGdiDisplayDriver : public CGdiDeviceDriver {
+class CGdiDisplayDriver final : public CGdiDeviceDriver {
  public:
   explicit CGdiDisplayDriver(HDC hDC);
   ~CGdiDisplayDriver() override;
@@ -229,7 +229,7 @@ class CGdiDisplayDriver : public CGdiDeviceDriver {
                              int render_flags);
 };
 
-class CGdiPrinterDriver : public CGdiDeviceDriver {
+class CGdiPrinterDriver final : public CGdiDeviceDriver {
  public:
   explicit CGdiPrinterDriver(HDC hDC);
   ~CGdiPrinterDriver() override;
@@ -269,7 +269,7 @@ class CGdiPrinterDriver : public CGdiDeviceDriver {
   const int m_VertSize;
 };
 
-class CPSPrinterDriver : public RenderDeviceDriverIface {
+class CPSPrinterDriver final : public RenderDeviceDriverIface {
  public:
   CPSPrinterDriver(HDC hDC, WindowsPrintMode mode, bool bCmykOutput);
   ~CPSPrinterDriver() override;
@@ -334,7 +334,7 @@ class CPSPrinterDriver : public RenderDeviceDriverIface {
   CFX_PSRenderer m_PSRenderer;
 };
 
-class CTextOnlyPrinterDriver : public RenderDeviceDriverIface {
+class CTextOnlyPrinterDriver final : public RenderDeviceDriverIface {
  public:
   explicit CTextOnlyPrinterDriver(HDC hDC);
   ~CTextOnlyPrinterDriver() override;