diff --git a/samples/pdfium_test.cc b/samples/pdfium_test.cc
index 36db5ff..87f8975 100644
--- a/samples/pdfium_test.cc
+++ b/samples/pdfium_test.cc
@@ -176,7 +176,7 @@
   return flags;
 }
 
-Optional<std::string> ExpandDirectoryPath(const std::string& path) {
+absl::optional<std::string> ExpandDirectoryPath(const std::string& path) {
 #if defined(WORDEXP_AVAILABLE)
   wordexp_t expansion;
   if (wordexp(path.c_str(), &expansion, 0) != 0 || expansion.we_wordc < 1) {
@@ -185,7 +185,7 @@
   }
   // Need to contruct the return value before hand, since wordfree will
   // deallocate |expansion|.
-  Optional<std::string> ret_val = {expansion.we_wordv[0]};
+  absl::optional<std::string> ret_val = {expansion.we_wordv[0]};
   wordfree(&expansion);
   return ret_val;
 #else
@@ -193,7 +193,7 @@
 #endif  // WORDEXP_AVAILABLE
 }
 
-Optional<const char*> GetCustomFontPath(const Options& options) {
+absl::optional<const char*> GetCustomFontPath(const Options& options) {
 #if defined(__APPLE__) || (defined(__linux__) && !defined(__ANDROID__))
   // Set custom font path to an empty path. This avoids the fallback to default
   // font paths.
@@ -533,7 +533,7 @@
         return false;
       }
       std::string path = value;
-      Optional<std::string> expanded_path = ExpandDirectoryPath(path);
+      absl::optional<std::string> expanded_path = ExpandDirectoryPath(path);
       if (!expanded_path.has_value()) {
         fprintf(stderr, "Failed to expand --font-dir, %s\n", path.c_str());
         return false;
@@ -588,7 +588,7 @@
         return false;
       }
       std::string path = value;
-      Optional<std::string> expanded_path = ExpandDirectoryPath(path);
+      absl::optional<std::string> expanded_path = ExpandDirectoryPath(path);
       if (!expanded_path.has_value()) {
         fprintf(stderr, "Failed to expand --bin-dir, %s\n", path.c_str());
         return false;
@@ -1224,7 +1224,7 @@
 #endif  // PDF_ENABLE_V8
 
   const char* path_array[2] = {nullptr, nullptr};
-  Optional<const char*> custom_font_path = GetCustomFontPath(options);
+  absl::optional<const char*> custom_font_path = GetCustomFontPath(options);
   if (custom_font_path.has_value()) {
     path_array[0] = custom_font_path.value();
     config.m_pUserFontPaths = path_array;
diff --git a/testing/scoped_set_tz.h b/testing/scoped_set_tz.h
index 19c633c..68269b9 100644
--- a/testing/scoped_set_tz.h
+++ b/testing/scoped_set_tz.h
@@ -20,7 +20,7 @@
   ~ScopedSetTZ();
 
  private:
-  Optional<std::string> old_tz_;
+  absl::optional<std::string> old_tz_;
 };
 
 #endif  // TESTING_SCOPED_SET_TZ_H_
diff --git a/third_party/base/template_util.h b/third_party/base/template_util.h
index b5e1a1e..2e26a8b 100644
--- a/third_party/base/template_util.h
+++ b/third_party/base/template_util.h
@@ -131,8 +131,9 @@
 #if defined(__GNUC__) && !defined(__clang__) && __GNUC__ <= 7
 // Workaround for g++7 and earlier family.
 // Due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80654, without this
-// Optional<std::vector<T>> where T is non-copyable causes a compile error.
-// As we know it is not trivially copy constructible, explicitly declare so.
+// absl::optional<std::vector<T>> where T is non-copyable causes a compile
+// error. As we know it is not trivially copy constructible, explicitly declare
+// so.
 template <typename T>
 struct is_trivially_copy_constructible
     : std::is_trivially_copy_constructible<T> {};
diff --git a/xfa/fgas/font/cfgas_fontmgr.h b/xfa/fgas/font/cfgas_fontmgr.h
index 8cab66d..ed67cb9 100644
--- a/xfa/fgas/font/cfgas_fontmgr.h
+++ b/xfa/fgas/font/cfgas_fontmgr.h
@@ -147,7 +147,7 @@
   std::deque<FX_FONTDESCRIPTOR> m_FontFaces;
 #else
   std::vector<std::unique_ptr<CFGAS_FontDescriptor>> m_InstalledFonts;
-  std::map<uint32_t, Optional<std::vector<CFGAS_FontDescriptorInfo>>>
+  std::map<uint32_t, absl::optional<std::vector<CFGAS_FontDescriptorInfo>>>
       m_Hash2CandidateList;
 #endif  // defined(OS_WIN)
 };
diff --git a/xfa/fgas/font/cfgas_gefont.cpp b/xfa/fgas/font/cfgas_gefont.cpp
index bdbc5e8..9ab418a 100644
--- a/xfa/fgas/font/cfgas_gefont.cpp
+++ b/xfa/fgas/font/cfgas_gefont.cpp
@@ -152,7 +152,7 @@
   return dwStyles;
 }
 
-Optional<uint16_t> CFGAS_GEFont::GetCharWidth(wchar_t wUnicode) {
+absl::optional<uint16_t> CFGAS_GEFont::GetCharWidth(wchar_t wUnicode) {
   auto it = m_CharWidthMap.find(wUnicode);
   if (it != m_CharWidthMap.end())
     return it->second;
@@ -177,7 +177,7 @@
   return width;
 }
 
-Optional<FX_RECT> CFGAS_GEFont::GetCharBBox(wchar_t wUnicode) {
+absl::optional<FX_RECT> CFGAS_GEFont::GetCharBBox(wchar_t wUnicode) {
   auto it = m_BBoxMap.find(wUnicode);
   if (it != m_BBoxMap.end())
     return it->second;
@@ -191,7 +191,7 @@
   if (pFont.Get() != this)
     return pFont->GetCharBBox(wUnicode);
 
-  Optional<FX_RECT> rtBBox = m_pFont->GetGlyphBBox(iGlyph);
+  absl::optional<FX_RECT> rtBBox = m_pFont->GetGlyphBBox(iGlyph);
   if (rtBBox.has_value())
     m_BBoxMap[wUnicode] = rtBBox.value();
 
diff --git a/xfa/fgas/font/cfgas_gefont.h b/xfa/fgas/font/cfgas_gefont.h
index b11dbbf..741958a 100644
--- a/xfa/fgas/font/cfgas_gefont.h
+++ b/xfa/fgas/font/cfgas_gefont.h
@@ -40,11 +40,11 @@
                                                const ByteString& font_family);
 
   uint32_t GetFontStyles() const;
-  Optional<uint16_t> GetCharWidth(wchar_t wUnicode);
+  absl::optional<uint16_t> GetCharWidth(wchar_t wUnicode);
   int32_t GetGlyphIndex(wchar_t wUnicode);
   int32_t GetAscent() const;
   int32_t GetDescent() const;
-  Optional<FX_RECT> GetCharBBox(wchar_t wUnicode);
+  absl::optional<FX_RECT> GetCharBBox(wchar_t wUnicode);
 
   RetainPtr<CFGAS_GEFont> GetSubstFont(int32_t iGlyphIndex);
   CFX_Font* GetDevFont() const { return m_pFont.Get(); }
@@ -71,11 +71,11 @@
       bool bRecursive);
   WideString GetFamilyName() const;
 
-  Optional<uint32_t> m_dwLogFontStyle;
+  absl::optional<uint32_t> m_dwLogFontStyle;
   RetainPtr<CPDF_Font> m_pPDFFont;  // Must come before |m_pFont|.
   MaybeOwned<CFX_Font> m_pFont;     // Must come before |m_pFontEncoding|.
   std::unique_ptr<CFX_UnicodeEncodingEx> m_pFontEncoding;
-  std::map<wchar_t, Optional<uint16_t>> m_CharWidthMap;
+  std::map<wchar_t, absl::optional<uint16_t>> m_CharWidthMap;
   std::map<wchar_t, FX_RECT> m_BBoxMap;
   std::vector<RetainPtr<CFGAS_GEFont>> m_SubstFonts;
   std::map<wchar_t, RetainPtr<CFGAS_GEFont>> m_FontMapper;
diff --git a/xfa/fgas/layout/cfgas_rtfbreak.cpp b/xfa/fgas/layout/cfgas_rtfbreak.cpp
index 401bdfa..b290c2d 100644
--- a/xfa/fgas/layout/cfgas_rtfbreak.cpp
+++ b/xfa/fgas/layout/cfgas_rtfbreak.cpp
@@ -123,7 +123,7 @@
 }
 
 void CFGAS_RTFBreak::AppendChar_Combination(CFGAS_Char* pCurChar) {
-  Optional<uint16_t> iCharWidthRet;
+  absl::optional<uint16_t> iCharWidthRet;
   if (m_pFont) {
     iCharWidthRet = m_pFont->GetCharWidth(pCurChar->char_code());
   }
@@ -213,7 +213,7 @@
                pLastChar->GetCharType() == FX_CHARTYPE::kArabicAlef);
       FX_SAFE_INT32 iCharWidth = 0;
       if (m_pFont) {
-        Optional<uint16_t> iCharWidthRet = m_pFont->GetCharWidth(wForm);
+        absl::optional<uint16_t> iCharWidthRet = m_pFont->GetCharWidth(wForm);
         if (iCharWidthRet.has_value()) {
           iCharWidth = iCharWidthRet.value();
         } else {
@@ -242,7 +242,7 @@
                                       nullptr);
   FX_SAFE_INT32 iCharWidth = 0;
   if (m_pFont) {
-    Optional<uint16_t> iCharWidthRet = m_pFont->GetCharWidth(wForm);
+    absl::optional<uint16_t> iCharWidthRet = m_pFont->GetCharWidth(wForm);
     if (!iCharWidthRet.has_value())
       iCharWidthRet = m_pFont->GetCharWidth(pCurChar->char_code());
     iCharWidth = iCharWidthRet.value_or(0);
diff --git a/xfa/fgas/layout/cfgas_txtbreak.cpp b/xfa/fgas/layout/cfgas_txtbreak.cpp
index 3845f11..49e7031 100644
--- a/xfa/fgas/layout/cfgas_txtbreak.cpp
+++ b/xfa/fgas/layout/cfgas_txtbreak.cpp
@@ -64,7 +64,7 @@
     if (pLastChar &&
         (pLastChar->m_dwCharStyles & FX_TXTCHARSTYLE_ArabicShadda) == 0) {
       wchar_t wLast = pLastChar->char_code();
-      Optional<uint16_t> maybe_shadda;
+      absl::optional<uint16_t> maybe_shadda;
       if (wch == pdfium::arabic::kArabicShadda) {
         maybe_shadda = pdfium::arabic::GetArabicFromShaddaTable(wLast);
       } else if (wLast == pdfium::arabic::kArabicShadda) {
@@ -77,7 +77,7 @@
         pLastChar->m_iCharWidth = 0;
       }
     }
-    Optional<uint16_t> iCharWidthRet;
+    absl::optional<uint16_t> iCharWidthRet;
     if (m_pFont) {
       iCharWidthRet = m_pFont->GetCharWidth(wch);
     }
@@ -742,7 +742,7 @@
           } else if (i < iLength) {
             wNext = *pStr;
           }
-          Optional<uint16_t> maybe_shadda;
+          absl::optional<uint16_t> maybe_shadda;
           if (wch == pdfium::arabic::kArabicShadda) {
             maybe_shadda = pdfium::arabic::GetArabicFromShaddaTable(wNext);
           } else if (wNext == pdfium::arabic::kArabicShadda) {
@@ -833,7 +833,7 @@
           pCharPos->m_Origin.x += fOffset;
         }
         if (chartype == FX_CHARTYPE::kCombination) {
-          Optional<FX_RECT> rtBBox = pFont->GetCharBBox(wForm);
+          absl::optional<FX_RECT> rtBBox = pFont->GetCharBBox(wForm);
           if (rtBBox.has_value()) {
             pCharPos->m_Origin.y =
                 fYBase + fFontSize -
@@ -843,7 +843,7 @@
               wLast != pdfium::unicode::kZeroWidthNoBreakSpace) {
             if (pdfium::unicode::GetCharType(wLast) ==
                 FX_CHARTYPE::kCombination) {
-              Optional<FX_RECT> rtOtherBox = pFont->GetCharBBox(wLast);
+              absl::optional<FX_RECT> rtOtherBox = pFont->GetCharBBox(wLast);
               if (rtOtherBox.has_value()) {
                 pCharPos->m_Origin.y -=
                     fFontSize * rtOtherBox.value().Height() / iMaxHeight;
diff --git a/xfa/fgas/layout/fgas_arabic.cpp b/xfa/fgas/layout/fgas_arabic.cpp
index 1f71759..9327524 100644
--- a/xfa/fgas/layout/fgas_arabic.cpp
+++ b/xfa/fgas/layout/fgas_arabic.cpp
@@ -212,7 +212,7 @@
   return (eNext < FX_CHARTYPE::kArabicAlef) ? ft->wFinal : ft->wMedial;
 }
 
-Optional<wchar_t> GetArabicFromShaddaTable(wchar_t shadda) {
+absl::optional<wchar_t> GetArabicFromShaddaTable(wchar_t shadda) {
   if (shadda < kFirstShaddaTableEntry || shadda > kLastShaddaTableEntry)
     return absl::nullopt;
 
diff --git a/xfa/fgas/layout/fgas_arabic.h b/xfa/fgas/layout/fgas_arabic.h
index d7fa64c..f141bd0 100644
--- a/xfa/fgas/layout/fgas_arabic.h
+++ b/xfa/fgas/layout/fgas_arabic.h
@@ -23,7 +23,7 @@
 wchar_t GetFormChar(const CFGAS_Char* cur,
                     const CFGAS_Char* prev,
                     const CFGAS_Char* next);
-Optional<wchar_t> GetArabicFromShaddaTable(wchar_t shadda);
+absl::optional<wchar_t> GetArabicFromShaddaTable(wchar_t shadda);
 
 }  // namespace arabic
 }  // namespace pdfium
diff --git a/xfa/fwl/cfwl_barcode.h b/xfa/fwl/cfwl_barcode.h
index 7700650..82020ba 100644
--- a/xfa/fwl/cfwl_barcode.h
+++ b/xfa/fwl/cfwl_barcode.h
@@ -62,17 +62,17 @@
 
   BC_TYPE m_type = BC_TYPE::kUnknown;
   Status m_eStatus = Status::kNormal;
-  Optional<BC_TEXT_LOC> m_eTextLocation;
-  Optional<BC_CHAR_ENCODING> m_eCharEncoding;
-  Optional<bool> m_bCalChecksum;
-  Optional<bool> m_bPrintChecksum;
-  Optional<char> m_cStartChar;
-  Optional<char> m_cEndChar;
-  Optional<int8_t> m_nWideNarrowRatio;
-  Optional<int32_t> m_nModuleHeight;
-  Optional<int32_t> m_nModuleWidth;
-  Optional<int32_t> m_nDataLength;
-  Optional<int32_t> m_nECLevel;
+  absl::optional<BC_TEXT_LOC> m_eTextLocation;
+  absl::optional<BC_CHAR_ENCODING> m_eCharEncoding;
+  absl::optional<bool> m_bCalChecksum;
+  absl::optional<bool> m_bPrintChecksum;
+  absl::optional<char> m_cStartChar;
+  absl::optional<char> m_cEndChar;
+  absl::optional<int8_t> m_nWideNarrowRatio;
+  absl::optional<int32_t> m_nModuleHeight;
+  absl::optional<int32_t> m_nModuleWidth;
+  absl::optional<int32_t> m_nDataLength;
+  absl::optional<int32_t> m_nECLevel;
   std::unique_ptr<CFX_Barcode> m_pBarcodeEngine;
 };
 
diff --git a/xfa/fwl/cfwl_combobox.h b/xfa/fwl/cfwl_combobox.h
index 029f3e9..695d373 100644
--- a/xfa/fwl/cfwl_combobox.h
+++ b/xfa/fwl/cfwl_combobox.h
@@ -72,8 +72,8 @@
     return EditCanCopy();
   }
   bool EditCanSelectAll() const { return m_pEdit->GetTextLength() > 0; }
-  Optional<WideString> EditCopy() const { return m_pEdit->Copy(); }
-  Optional<WideString> EditCut() { return m_pEdit->Cut(); }
+  absl::optional<WideString> EditCopy() const { return m_pEdit->Copy(); }
+  absl::optional<WideString> EditCut() { return m_pEdit->Cut(); }
   bool EditPaste(const WideString& wsPaste) { return m_pEdit->Paste(wsPaste); }
   void EditSelectAll() { m_pEdit->SelectAll(); }
   void EditDelete() { m_pEdit->ClearText(); }
diff --git a/xfa/fwl/cfwl_datetimepicker.cpp b/xfa/fwl/cfwl_datetimepicker.cpp
index 3d19bf5..085df3c 100644
--- a/xfa/fwl/cfwl_datetimepicker.cpp
+++ b/xfa/fwl/cfwl_datetimepicker.cpp
@@ -436,11 +436,11 @@
   m_pEdit->ClearSelection();
 }
 
-Optional<WideString> CFWL_DateTimePicker::Copy() {
+absl::optional<WideString> CFWL_DateTimePicker::Copy() {
   return m_pEdit->Copy();
 }
 
-Optional<WideString> CFWL_DateTimePicker::Cut() {
+absl::optional<WideString> CFWL_DateTimePicker::Cut() {
   return m_pEdit->Cut();
 }
 
diff --git a/xfa/fwl/cfwl_datetimepicker.h b/xfa/fwl/cfwl_datetimepicker.h
index 9c144a7..060a780 100644
--- a/xfa/fwl/cfwl_datetimepicker.h
+++ b/xfa/fwl/cfwl_datetimepicker.h
@@ -60,8 +60,8 @@
   std::pair<size_t, size_t> GetSelection() const {
     return m_pEdit->GetSelection();
   }
-  Optional<WideString> Copy();
-  Optional<WideString> Cut();
+  absl::optional<WideString> Copy();
+  absl::optional<WideString> Cut();
   bool Paste(const WideString& wsPaste);
   bool Undo();
   bool Redo();
diff --git a/xfa/fwl/cfwl_edit.cpp b/xfa/fwl/cfwl_edit.cpp
index d13fc55..534b45e 100644
--- a/xfa/fwl/cfwl_edit.cpp
+++ b/xfa/fwl/cfwl_edit.cpp
@@ -204,14 +204,14 @@
   m_pEditEngine->SetAliasChar(wAlias);
 }
 
-Optional<WideString> CFWL_Edit::Copy() {
+absl::optional<WideString> CFWL_Edit::Copy() {
   if (!m_pEditEngine->HasSelection())
     return absl::nullopt;
 
   return m_pEditEngine->GetSelectedText();
 }
 
-Optional<WideString> CFWL_Edit::Cut() {
+absl::optional<WideString> CFWL_Edit::Cut() {
   if (!m_pEditEngine->HasSelection())
     return absl::nullopt;
 
diff --git a/xfa/fwl/cfwl_edit.h b/xfa/fwl/cfwl_edit.h
index 258926b..a9ce04b 100644
--- a/xfa/fwl/cfwl_edit.h
+++ b/xfa/fwl/cfwl_edit.h
@@ -80,8 +80,8 @@
   int32_t GetLimit() const;
   void SetLimit(int32_t nLimit);
   void SetAliasChar(wchar_t wAlias);
-  Optional<WideString> Copy();
-  Optional<WideString> Cut();
+  absl::optional<WideString> Copy();
+  absl::optional<WideString> Cut();
   bool Paste(const WideString& wsPaste);
   bool Undo();
   bool Redo();
diff --git a/xfa/fxfa/cxfa_ffbarcode.cpp b/xfa/fxfa/cxfa_ffbarcode.cpp
index ba9e741..ad9b71f 100644
--- a/xfa/fxfa/cxfa_ffbarcode.cpp
+++ b/xfa/fxfa/cxfa_ffbarcode.cpp
@@ -93,7 +93,8 @@
     {0xfb48155c, "code3Of9", BC_TYPE::kCode39},
 };
 
-Optional<BC_CHAR_ENCODING> CharEncodingFromString(const WideString& value) {
+absl::optional<BC_CHAR_ENCODING> CharEncodingFromString(
+    const WideString& value) {
   if (value.CompareNoCase(L"UTF-16"))
     return BC_CHAR_ENCODING::kUnicode;
   if (value.CompareNoCase(L"UTF-8"))
@@ -101,7 +102,7 @@
   return absl::nullopt;
 }
 
-Optional<BC_TEXT_LOC> TextLocFromAttribute(XFA_AttributeValue value) {
+absl::optional<BC_TEXT_LOC> TextLocFromAttribute(XFA_AttributeValue value) {
   switch (value) {
     case XFA_AttributeValue::None:
       return BC_TEXT_LOC::kNone;
@@ -197,56 +198,57 @@
   auto* pBarCodeWidget = static_cast<CFWL_Barcode*>(GetNormalWidget());
   pBarCodeWidget->SetType(bc_type);
 
-  Optional<WideString> encoding_string = barcode_->GetCharEncoding();
+  absl::optional<WideString> encoding_string = barcode_->GetCharEncoding();
   if (encoding_string.has_value()) {
-    Optional<BC_CHAR_ENCODING> encoding =
+    absl::optional<BC_CHAR_ENCODING> encoding =
         CharEncodingFromString(encoding_string.value());
     if (encoding.has_value())
       pBarCodeWidget->SetCharEncoding(encoding.value());
   }
 
-  Optional<bool> calcChecksum = barcode_->GetChecksum();
+  absl::optional<bool> calcChecksum = barcode_->GetChecksum();
   if (calcChecksum.has_value())
     pBarCodeWidget->SetCalChecksum(calcChecksum.value());
 
-  Optional<int32_t> dataLen = barcode_->GetDataLength();
+  absl::optional<int32_t> dataLen = barcode_->GetDataLength();
   if (dataLen.has_value())
     pBarCodeWidget->SetDataLength(dataLen.value());
 
-  Optional<char> startChar = barcode_->GetStartChar();
+  absl::optional<char> startChar = barcode_->GetStartChar();
   if (startChar.has_value())
     pBarCodeWidget->SetStartChar(startChar.value());
 
-  Optional<char> endChar = barcode_->GetEndChar();
+  absl::optional<char> endChar = barcode_->GetEndChar();
   if (endChar.has_value())
     pBarCodeWidget->SetEndChar(endChar.value());
 
-  Optional<int32_t> ecLevel = barcode_->GetECLevel();
+  absl::optional<int32_t> ecLevel = barcode_->GetECLevel();
   if (ecLevel.has_value())
     pBarCodeWidget->SetErrorCorrectionLevel(ecLevel.value());
 
-  Optional<int32_t> width = barcode_->GetModuleWidth();
+  absl::optional<int32_t> width = barcode_->GetModuleWidth();
   if (width.has_value())
     pBarCodeWidget->SetModuleWidth(width.value());
 
-  Optional<int32_t> height = barcode_->GetModuleHeight();
+  absl::optional<int32_t> height = barcode_->GetModuleHeight();
   if (height.has_value())
     pBarCodeWidget->SetModuleHeight(height.value());
 
-  Optional<bool> printCheck = barcode_->GetPrintChecksum();
+  absl::optional<bool> printCheck = barcode_->GetPrintChecksum();
   if (printCheck.has_value())
     pBarCodeWidget->SetPrintChecksum(printCheck.value());
 
-  Optional<XFA_AttributeValue> text_attr = barcode_->GetTextLocation();
+  absl::optional<XFA_AttributeValue> text_attr = barcode_->GetTextLocation();
   if (text_attr.has_value()) {
-    Optional<BC_TEXT_LOC> textLoc = TextLocFromAttribute(text_attr.value());
+    absl::optional<BC_TEXT_LOC> textLoc =
+        TextLocFromAttribute(text_attr.value());
     if (textLoc.has_value())
       pBarCodeWidget->SetTextLocation(textLoc.value());
   }
 
   // Truncated is currently not a supported flag.
 
-  Optional<int8_t> ratio = barcode_->GetWideNarrowRatio();
+  absl::optional<int8_t> ratio = barcode_->GetWideNarrowRatio();
   if (ratio.has_value())
     pBarCodeWidget->SetWideNarrowRatio(ratio.value());
 
diff --git a/xfa/fxfa/cxfa_ffcombobox.cpp b/xfa/fxfa/cxfa_ffcombobox.cpp
index bda6163..1bb4929 100644
--- a/xfa/fxfa/cxfa_ffcombobox.cpp
+++ b/xfa/fxfa/cxfa_ffcombobox.cpp
@@ -254,11 +254,11 @@
          ToComboBox(GetNormalWidget())->EditRedo();
 }
 
-Optional<WideString> CXFA_FFComboBox::Copy() {
+absl::optional<WideString> CXFA_FFComboBox::Copy() {
   return ToComboBox(GetNormalWidget())->EditCopy();
 }
 
-Optional<WideString> CXFA_FFComboBox::Cut() {
+absl::optional<WideString> CXFA_FFComboBox::Cut() {
   if (!m_pNode->IsChoiceListAllowTextEntry())
     return absl::nullopt;
 
diff --git a/xfa/fxfa/cxfa_ffcombobox.h b/xfa/fxfa/cxfa_ffcombobox.h
index 63d5640..c35a96a 100644
--- a/xfa/fxfa/cxfa_ffcombobox.h
+++ b/xfa/fxfa/cxfa_ffcombobox.h
@@ -37,8 +37,8 @@
   bool CanSelectAll() override;
   bool Undo() override;
   bool Redo() override;
-  Optional<WideString> Copy() override;
-  Optional<WideString> Cut() override;
+  absl::optional<WideString> Copy() override;
+  absl::optional<WideString> Cut() override;
   bool Paste(const WideString& wsPaste) override;
   void SelectAll() override;
   void Delete() override;
diff --git a/xfa/fxfa/cxfa_ffdatetimeedit.cpp b/xfa/fxfa/cxfa_ffdatetimeedit.cpp
index 8e7ea30..cb3a1cd 100644
--- a/xfa/fxfa/cxfa_ffdatetimeedit.cpp
+++ b/xfa/fxfa/cxfa_ffdatetimeedit.cpp
@@ -92,7 +92,7 @@
   GetNormalWidget()->ModifyStyleExts(dwExtendedStyle, 0xFFFFFFFF);
 
   uint32_t dwEditStyles = 0;
-  Optional<int32_t> numCells = m_pNode->GetNumberOfCells();
+  absl::optional<int32_t> numCells = m_pNode->GetNumberOfCells();
   if (numCells.has_value() && numCells.value() > 0) {
     dwEditStyles |= FWL_STYLEEXT_EDT_CombText;
     pPicker->SetEditLimit(numCells.value());
@@ -244,7 +244,7 @@
   return GetPickerWidget()->GetEditTextLength() > 0;
 }
 
-Optional<WideString> CXFA_FFDateTimeEdit::Copy() {
+absl::optional<WideString> CXFA_FFDateTimeEdit::Copy() {
   return GetPickerWidget()->Copy();
 }
 
@@ -256,7 +256,7 @@
   return GetPickerWidget()->Redo();
 }
 
-Optional<WideString> CXFA_FFDateTimeEdit::Cut() {
+absl::optional<WideString> CXFA_FFDateTimeEdit::Cut() {
   return GetPickerWidget()->Cut();
 }
 
diff --git a/xfa/fxfa/cxfa_ffdatetimeedit.h b/xfa/fxfa/cxfa_ffdatetimeedit.h
index 6a4d416..b20e703 100644
--- a/xfa/fxfa/cxfa_ffdatetimeedit.h
+++ b/xfa/fxfa/cxfa_ffdatetimeedit.h
@@ -39,8 +39,8 @@
   bool CanSelectAll() override;
   bool Undo() override;
   bool Redo() override;
-  Optional<WideString> Copy() override;
-  Optional<WideString> Cut() override;
+  absl::optional<WideString> Copy() override;
+  absl::optional<WideString> Cut() override;
   bool Paste(const WideString& wsPaste) override;
   void SelectAll() override;
   void Delete() override;
diff --git a/xfa/fxfa/cxfa_ffdocview.cpp b/xfa/fxfa/cxfa_ffdocview.cpp
index 8be2f1e..ae6eaca 100644
--- a/xfa/fxfa/cxfa_ffdocview.cpp
+++ b/xfa/fxfa/cxfa_ffdocview.cpp
@@ -452,7 +452,7 @@
     pRefNode = node->IsWidgetReady() ? node : nullptr;
   }
   WideString wsExpression = (!pRefNode ? L"$form." : L"") + wsName;
-  Optional<CFXJSE_Engine::ResolveResult> maybeResult =
+  absl::optional<CFXJSE_Engine::ResolveResult> maybeResult =
       pScriptContext->ResolveObjects(
           pRefNode, wsExpression.AsStringView(),
           Mask<XFA_ResolveFlag>{
@@ -649,7 +649,7 @@
     CFXJSE_Engine* pScriptContext =
         pWidgetNode->GetDocument()->GetScriptContext();
     WideString wsRef = item->GetRef();
-    Optional<CFXJSE_Engine::ResolveResult> maybeRS =
+    absl::optional<CFXJSE_Engine::ResolveResult> maybeRS =
         pScriptContext->ResolveObjects(
             pWidgetNode, wsRef.AsStringView(),
             Mask<XFA_ResolveFlag>{
diff --git a/xfa/fxfa/cxfa_ffnumericedit.cpp b/xfa/fxfa/cxfa_ffnumericedit.cpp
index 32903f4..8e18195 100644
--- a/xfa/fxfa/cxfa_ffnumericedit.cpp
+++ b/xfa/fxfa/cxfa_ffnumericedit.cpp
@@ -55,7 +55,7 @@
   if (!m_pNode->IsHorizontalScrollPolicyOff())
     dwExtendedStyle |= FWL_STYLEEXT_EDT_AutoHScroll;
 
-  Optional<int32_t> numCells = m_pNode->GetNumberOfCells();
+  absl::optional<int32_t> numCells = m_pNode->GetNumberOfCells();
   if (numCells.has_value() && numCells.value() > 0) {
     dwExtendedStyle |= FWL_STYLEEXT_EDT_CombText;
     pWidget->SetLimit(numCells.value());
diff --git a/xfa/fxfa/cxfa_ffpageview.cpp b/xfa/fxfa/cxfa_ffpageview.cpp
index 50399a8..3c160eb 100644
--- a/xfa/fxfa/cxfa_ffpageview.cpp
+++ b/xfa/fxfa/cxfa_ffpageview.cpp
@@ -426,7 +426,7 @@
     CXFA_Traverse* pTraverse =
         pTraversal->GetChild<CXFA_Traverse>(0, XFA_Element::Traverse, false);
     if (pTraverse) {
-      Optional<WideString> traverseWidgetName =
+      absl::optional<WideString> traverseWidgetName =
           pTraverse->JSObject()->TryAttribute(XFA_Attribute::Ref, true);
       if (traverseWidgetName.has_value())
         return FindWidgetByName(traverseWidgetName.value(), pWidget);
diff --git a/xfa/fxfa/cxfa_fftextedit.cpp b/xfa/fxfa/cxfa_fftextedit.cpp
index 38bdfee..6bf2503 100644
--- a/xfa/fxfa/cxfa_fftextedit.cpp
+++ b/xfa/fxfa/cxfa_fftextedit.cpp
@@ -100,7 +100,7 @@
   if (eType == XFA_Element::ExData)
     iMaxChars = 0;
 
-  Optional<int32_t> numCells = m_pNode->GetNumberOfCells();
+  absl::optional<int32_t> numCells = m_pNode->GetNumberOfCells();
   if (!numCells.has_value()) {
     pWidget->SetLimit(iMaxChars);
   } else if (numCells == 0) {
@@ -401,11 +401,11 @@
   return ToEdit(GetNormalWidget())->Redo();
 }
 
-Optional<WideString> CXFA_FFTextEdit::Copy() {
+absl::optional<WideString> CXFA_FFTextEdit::Copy() {
   return ToEdit(GetNormalWidget())->Copy();
 }
 
-Optional<WideString> CXFA_FFTextEdit::Cut() {
+absl::optional<WideString> CXFA_FFTextEdit::Cut() {
   return ToEdit(GetNormalWidget())->Cut();
 }
 
diff --git a/xfa/fxfa/cxfa_fftextedit.h b/xfa/fxfa/cxfa_fftextedit.h
index 2fb39ed..d680974 100644
--- a/xfa/fxfa/cxfa_fftextedit.h
+++ b/xfa/fxfa/cxfa_fftextedit.h
@@ -62,8 +62,8 @@
   bool CanSelectAll() override;
   bool Undo() override;
   bool Redo() override;
-  Optional<WideString> Copy() override;
-  Optional<WideString> Cut() override;
+  absl::optional<WideString> Copy() override;
+  absl::optional<WideString> Cut() override;
   bool Paste(const WideString& wsPaste) override;
   void SelectAll() override;
   void Delete() override;
diff --git a/xfa/fxfa/cxfa_ffwidget.cpp b/xfa/fxfa/cxfa_ffwidget.cpp
index 01008bf..95df80e 100644
--- a/xfa/fxfa/cxfa_ffwidget.cpp
+++ b/xfa/fxfa/cxfa_ffwidget.cpp
@@ -508,11 +508,11 @@
   return false;
 }
 
-Optional<WideString> CXFA_FFWidget::Copy() {
+absl::optional<WideString> CXFA_FFWidget::Copy() {
   return absl::nullopt;
 }
 
-Optional<WideString> CXFA_FFWidget::Cut() {
+absl::optional<WideString> CXFA_FFWidget::Cut() {
   return absl::nullopt;
 }
 
diff --git a/xfa/fxfa/cxfa_ffwidget.h b/xfa/fxfa/cxfa_ffwidget.h
index 5df2c70..45fc009 100644
--- a/xfa/fxfa/cxfa_ffwidget.h
+++ b/xfa/fxfa/cxfa_ffwidget.h
@@ -148,8 +148,8 @@
   virtual bool CanDeSelect();
   virtual bool Undo();
   virtual bool Redo();
-  virtual Optional<WideString> Copy();
-  virtual Optional<WideString> Cut();
+  virtual absl::optional<WideString> Copy();
+  virtual absl::optional<WideString> Cut();
   virtual bool Paste(const WideString& wsPaste);
   virtual void SelectAll();
   virtual void Delete();
diff --git a/xfa/fxfa/cxfa_textlayout.cpp b/xfa/fxfa/cxfa_textlayout.cpp
index bc29013..3f90538 100644
--- a/xfa/fxfa/cxfa_textlayout.cpp
+++ b/xfa/fxfa/cxfa_textlayout.cpp
@@ -812,7 +812,7 @@
           while (iTabCount-- > 0)
             wsText += L'\t';
         } else {
-          Optional<WideString> obj =
+          absl::optional<WideString> obj =
               m_pTextParser->GetEmbeddedObj(m_pTextProvider, pXMLNode);
           if (obj.has_value())
             wsText = obj.value();
diff --git a/xfa/fxfa/cxfa_textparser.cpp b/xfa/fxfa/cxfa_textparser.cpp
index e98f7be..1877eeb 100644
--- a/xfa/fxfa/cxfa_textparser.cpp
+++ b/xfa/fxfa/cxfa_textparser.cpp
@@ -351,7 +351,7 @@
   }
 
   if (pStyle) {
-    Optional<WideString> last_family = pStyle->GetLastFontFamily();
+    absl::optional<WideString> last_family = pStyle->GetLastFontFamily();
     if (last_family.has_value())
       wsFamily = last_family.value();
 
@@ -500,7 +500,7 @@
   return fLineHeight;
 }
 
-Optional<WideString> CXFA_TextParser::GetEmbeddedObj(
+absl::optional<WideString> CXFA_TextParser::GetEmbeddedObj(
     const CXFA_TextProvider* pTextProvider,
     const CFX_XMLNode* pXMLNode) {
   if (!pXMLNode)
diff --git a/xfa/fxfa/cxfa_textparser.h b/xfa/fxfa/cxfa_textparser.h
index f6d633d..7a7c306 100644
--- a/xfa/fxfa/cxfa_textparser.h
+++ b/xfa/fxfa/cxfa_textparser.h
@@ -110,8 +110,9 @@
                       bool bFirst,
                       float fVerScale) const;
 
-  Optional<WideString> GetEmbeddedObj(const CXFA_TextProvider* pTextProvider,
-                                      const CFX_XMLNode* pXMLNode);
+  absl::optional<WideString> GetEmbeddedObj(
+      const CXFA_TextProvider* pTextProvider,
+      const CFX_XMLNode* pXMLNode);
   Context* GetParseContextFromMap(const CFX_XMLNode* pXMLNode);
 
  protected:
diff --git a/xfa/fxfa/cxfa_textprovider.cpp b/xfa/fxfa/cxfa_textprovider.cpp
index f93b788..76449ed 100644
--- a/xfa/fxfa/cxfa_textprovider.cpp
+++ b/xfa/fxfa/cxfa_textprovider.cpp
@@ -53,8 +53,9 @@
 
     CXFA_Node* pChildNode = pValueNode->GetFirstChild();
     if (pChildNode && pChildNode->GetElementType() == XFA_Element::ExData) {
-      Optional<WideString> contentType = pChildNode->JSObject()->TryAttribute(
-          XFA_Attribute::ContentType, false);
+      absl::optional<WideString> contentType =
+          pChildNode->JSObject()->TryAttribute(XFA_Attribute::ContentType,
+                                               false);
       if (contentType.has_value() &&
           contentType.value().EqualsASCII("text/html")) {
         *bRichText = true;
@@ -76,8 +77,9 @@
 
     CXFA_Node* pChildNode = pValueNode->GetFirstChild();
     if (pChildNode && pChildNode->GetElementType() == XFA_Element::ExData) {
-      Optional<WideString> contentType = pChildNode->JSObject()->TryAttribute(
-          XFA_Attribute::ContentType, false);
+      absl::optional<WideString> contentType =
+          pChildNode->JSObject()->TryAttribute(XFA_Attribute::ContentType,
+                                               false);
       if (contentType.has_value() &&
           contentType.value().EqualsASCII("text/html")) {
         *bRichText = true;
@@ -130,7 +132,7 @@
   return !m_pNode->TryWidth().has_value();
 }
 
-Optional<WideString> CXFA_TextProvider::GetEmbeddedObj(
+absl::optional<WideString> CXFA_TextProvider::GetEmbeddedObj(
     const WideString& wsAttr) const {
   if (m_eType != Type::kText)
     return absl::nullopt;
diff --git a/xfa/fxfa/cxfa_textprovider.h b/xfa/fxfa/cxfa_textprovider.h
index 138e429..f0c9fa1 100644
--- a/xfa/fxfa/cxfa_textprovider.h
+++ b/xfa/fxfa/cxfa_textprovider.h
@@ -37,7 +37,7 @@
   CXFA_Para* GetParaIfExists();
   CXFA_Font* GetFontIfExists();
   bool IsCheckButtonAndAutoWidth() const;
-  Optional<WideString> GetEmbeddedObj(const WideString& wsAttr) const;
+  absl::optional<WideString> GetEmbeddedObj(const WideString& wsAttr) const;
 
  private:
   CXFA_TextProvider(CXFA_Node* pNode, Type eType);
diff --git a/xfa/fxfa/fm2js/cxfa_fmexpression.cpp b/xfa/fxfa/fm2js/cxfa_fmexpression.cpp
index da7cd40..a080b46 100644
--- a/xfa/fxfa/fm2js/cxfa_fmexpression.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmexpression.cpp
@@ -771,7 +771,7 @@
   ContainerTrace(visitor, expressions_);
 }
 
-Optional<CFX_WideTextBuf> CXFA_FMAST::ToJavaScript() const {
+absl::optional<CFX_WideTextBuf> CXFA_FMAST::ToJavaScript() const {
   CFX_WideTextBuf js;
   if (expressions_.empty()) {
     js << "// comments only";
diff --git a/xfa/fxfa/fm2js/cxfa_fmexpression.h b/xfa/fxfa/fm2js/cxfa_fmexpression.h
index 15e2ca1..0e015f7 100644
--- a/xfa/fxfa/fm2js/cxfa_fmexpression.h
+++ b/xfa/fxfa/fm2js/cxfa_fmexpression.h
@@ -595,7 +595,7 @@
   ~CXFA_FMAST();
 
   void Trace(cppgc::Visitor* visitor) const;
-  Optional<CFX_WideTextBuf> ToJavaScript() const;
+  absl::optional<CFX_WideTextBuf> ToJavaScript() const;
 
  private:
   explicit CXFA_FMAST(
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.cpp b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
index 1625d2b..89a2faa 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
@@ -651,7 +651,7 @@
 
     switch (m_token.m_type) {
       case TOKlparen: {
-        Optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
+        absl::optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
             expressions = ParseArgumentList();
         if (!expressions.has_value())
           return nullptr;
@@ -682,7 +682,7 @@
         if (!NextToken())
           return nullptr;
         if (m_token.m_type == TOKlparen) {
-          Optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
+          absl::optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
               expressions = ParseArgumentList();
           if (!expressions.has_value())
             return nullptr;
@@ -800,7 +800,7 @@
 
 // Argument lists are zero or more comma seperated simple expressions found
 // between '(' and ')'
-Optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
+absl::optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
 CXFA_FMParser::ParseArgumentList() {
   if (m_token.m_type != TOKlparen || !NextToken())
     return absl::nullopt;
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.h b/xfa/fxfa/fm2js/cxfa_fmparser.h
index fa32f5a..8d1ab69 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser.h
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.h
@@ -60,7 +60,7 @@
   CXFA_FMSimpleExpression* ParsePostExpression(CXFA_FMSimpleExpression* e);
   CXFA_FMSimpleExpression* ParseIndexExpression();
   CXFA_FMSimpleExpression* ParseLiteral();
-  Optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
+  absl::optional<std::vector<cppgc::Member<CXFA_FMSimpleExpression>>>
   ParseArgumentList();
 
   UnownedPtr<cppgc::Heap> const m_heap;
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp b/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp
index ade2b05..74f69d9 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp
@@ -19,7 +19,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   // TODO(dsinclair): This is a little weird .....
   EXPECT_STREQ(L"// comments only", buf.value().MakeString().c_str());
@@ -35,7 +35,7 @@
   // EXPECT_TRUE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(L"// comments only", buf.value().MakeString().c_str());
 }
@@ -65,7 +65,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -135,7 +135,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_EQ(ret, buf.value().AsStringView());
 }
@@ -201,7 +201,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -240,7 +240,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -329,7 +329,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -371,7 +371,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -403,7 +403,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -437,7 +437,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -471,7 +471,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
@@ -505,7 +505,7 @@
   EXPECT_FALSE(parser.HasError());
 
   CXFA_FMToJavaScriptDepth::Reset();
-  Optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
+  absl::optional<CFX_WideTextBuf> buf = ast->ToJavaScript();
   ASSERT_TRUE(buf.has_value());
   EXPECT_STREQ(ret, buf.value().MakeString().c_str());
 }
diff --git a/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp b/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp
index ebe30d5..a9778c1 100644
--- a/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp
+++ b/xfa/fxfa/layout/cxfa_contentlayoutprocessor.cpp
@@ -93,14 +93,14 @@
 
   CFX_SizeF containerSize;
   if (eType == XFA_Element::Subform || eType == XFA_Element::ExclGroup) {
-    Optional<CXFA_Measurement> wValue =
+    absl::optional<CXFA_Measurement> wValue =
         pFormNode->JSObject()->TryMeasure(XFA_Attribute::W, false);
     if (wValue.has_value() && wValue->GetValue() > kXFALayoutPrecision) {
       containerSize.width = wValue->ToUnit(XFA_Unit::Pt);
       *bContainerWidthAutoSize = false;
     }
 
-    Optional<CXFA_Measurement> hValue =
+    absl::optional<CXFA_Measurement> hValue =
         pFormNode->JSObject()->TryMeasure(XFA_Attribute::H, false);
     if (hValue.has_value() && hValue->GetValue() > kXFALayoutPrecision) {
       containerSize.height = hValue->ToUnit(XFA_Unit::Pt);
@@ -109,14 +109,14 @@
   }
 
   if (*bContainerWidthAutoSize && eType == XFA_Element::Subform) {
-    Optional<CXFA_Measurement> maxW =
+    absl::optional<CXFA_Measurement> maxW =
         pFormNode->JSObject()->TryMeasure(XFA_Attribute::MaxW, false);
     if (maxW.has_value() && maxW->GetValue() > kXFALayoutPrecision) {
       containerSize.width = maxW->ToUnit(XFA_Unit::Pt);
       *bContainerWidthAutoSize = false;
     }
 
-    Optional<CXFA_Measurement> maxH =
+    absl::optional<CXFA_Measurement> maxH =
         pFormNode->JSObject()->TryMeasure(XFA_Attribute::MaxH, false);
     if (maxH.has_value() && maxH->GetValue() > kXFALayoutPrecision) {
       containerSize.height = maxH->ToUnit(XFA_Unit::Pt);
@@ -139,12 +139,12 @@
   if (bContainerWidthAutoSize) {
     componentSize.width = fContentCalculatedWidth;
     if (pMarginNode) {
-      Optional<CXFA_Measurement> leftInset =
+      absl::optional<CXFA_Measurement> leftInset =
           pMarginNode->JSObject()->TryMeasure(XFA_Attribute::LeftInset, false);
       if (leftInset.has_value())
         componentSize.width += leftInset->ToUnit(XFA_Unit::Pt);
 
-      Optional<CXFA_Measurement> rightInset =
+      absl::optional<CXFA_Measurement> rightInset =
           pMarginNode->JSObject()->TryMeasure(XFA_Attribute::RightInset, false);
       if (rightInset.has_value())
         componentSize.width += rightInset->ToUnit(XFA_Unit::Pt);
@@ -154,12 +154,12 @@
   if (bContainerHeightAutoSize) {
     componentSize.height = fContentCalculatedHeight;
     if (pMarginNode) {
-      Optional<CXFA_Measurement> topInset =
+      absl::optional<CXFA_Measurement> topInset =
           pMarginNode->JSObject()->TryMeasure(XFA_Attribute::TopInset, false);
       if (topInset.has_value())
         componentSize.height += topInset->ToUnit(XFA_Unit::Pt);
 
-      Optional<CXFA_Measurement> bottomInset =
+      absl::optional<CXFA_Measurement> bottomInset =
           pMarginNode->JSObject()->TryMeasure(XFA_Attribute::BottomInset,
                                               false);
       if (bottomInset.has_value())
@@ -338,7 +338,7 @@
 
 XFA_AttributeValue GetLayout(CXFA_Node* pFormNode, bool* bRootForceTb) {
   *bRootForceTb = false;
-  Optional<XFA_AttributeValue> layoutMode =
+  absl::optional<XFA_AttributeValue> layoutMode =
       pFormNode->JSObject()->TryEnum(XFA_Attribute::Layout, false);
   if (layoutMode.has_value())
     return layoutMode.value();
@@ -367,7 +367,7 @@
     if (!bPreFind)
       eKeepType = XFA_Attribute::Next;
 
-    Optional<XFA_AttributeValue> previous =
+    absl::optional<XFA_AttributeValue> previous =
         pKeep->JSObject()->TryEnum(eKeepType, false);
     if (previous == XFA_AttributeValue::ContentArea ||
         previous == XFA_AttributeValue::PageArea) {
@@ -383,7 +383,7 @@
   if (!bPreFind)
     eKeepType = XFA_Attribute::Previous;
 
-  Optional<XFA_AttributeValue> next =
+  absl::optional<XFA_AttributeValue> next =
       pKeep->JSObject()->TryEnum(eKeepType, false);
   if (next == XFA_AttributeValue::ContentArea ||
       next == XFA_AttributeValue::PageArea) {
@@ -392,7 +392,7 @@
   return false;
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage> FindBreakNode(
+absl::optional<CXFA_ContentLayoutProcessor::Stage> FindBreakNode(
     CXFA_Node* pContainerNode,
     bool bBreakBefore,
     CXFA_Node** pCurActionNode) {
@@ -493,7 +493,7 @@
       while (bChanged) {
         bChanged = false;
         {
-          Optional<float> fRelSplitPos = pFormNode->FindSplitPos(
+          absl::optional<float> fRelSplitPos = pFormNode->FindSplitPos(
               pNotify->GetFFDoc()->GetDocView(), pLayoutItem->GetIndex(),
               *fProposedSplitPos - fCurVerticalOffset);
           if (fRelSplitPos.has_value()) {
@@ -872,7 +872,7 @@
       break;
   }
 
-  Optional<Stage> ret;
+  absl::optional<Stage> ret;
   switch (nCurStage) {
     case Stage::kKeep:
       ret = HandleKeep(pChildContainer->GetFirstChild(), &pCurActionNode);
@@ -930,7 +930,7 @@
   return {Stage::kDone, nullptr};
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::ProcessKeepNodesForCheckNext(
     CXFA_Node** pCurActionNode,
     CXFA_Node** pNextContainer,
@@ -961,7 +961,7 @@
     return absl::nullopt;
   }
 
-  Optional<Stage> ret =
+  absl::optional<Stage> ret =
       FindBreakNode((*pNextContainer)->GetFirstChild(), true, pCurActionNode);
   if (!ret.has_value()) {
     *pNextContainer = m_pKeepHeadNode;
@@ -972,7 +972,7 @@
   return ret;
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::ProcessKeepNodesForBreakBefore(
     CXFA_Node** pCurActionNode,
     CXFA_Node* pContainerNode) {
@@ -1643,7 +1643,7 @@
           if (!bUseBreakControl || !m_pViewLayoutProcessor)
             break;
 
-          Optional<CXFA_ViewLayoutProcessor::BreakData> break_data =
+          absl::optional<CXFA_ViewLayoutProcessor::BreakData> break_data =
               m_pViewLayoutProcessor->ProcessBreakBefore(m_pCurChildNode);
           if (!break_data.has_value() || !break_data.value().bCreatePage ||
               GetFormNode()->GetElementType() == XFA_Element::Form) {
@@ -1684,7 +1684,7 @@
           if (!bUseBreakControl || !m_pViewLayoutProcessor)
             break;
 
-          Optional<CXFA_ViewLayoutProcessor::BreakData> break_data =
+          absl::optional<CXFA_ViewLayoutProcessor::BreakData> break_data =
               m_pViewLayoutProcessor->ProcessBreakAfter(m_pCurChildNode);
           if (!break_data.has_value() ||
               GetFormNode()->GetElementType() == XFA_Element::Form) {
@@ -2430,7 +2430,7 @@
       pFormNode = pLayoutContext->m_pOverflowNode.Get();
       bUseInherited = true;
     }
-    Optional<CXFA_ViewLayoutProcessor::OverflowData> overflow_data =
+    absl::optional<CXFA_ViewLayoutProcessor::OverflowData> overflow_data =
         m_pViewLayoutProcessor->ProcessOverflow(pFormNode, false);
     if (overflow_data.has_value()) {
       pOverflowLeaderNode = overflow_data.value().pLeader;
@@ -2632,7 +2632,7 @@
   if (pProcessor->GetFormNode()->GetIntact() == XFA_AttributeValue::None &&
       eLayout == XFA_AttributeValue::Tb) {
     if (m_pViewLayoutProcessor) {
-      Optional<CXFA_ViewLayoutProcessor::OverflowData> overflow_data =
+      absl::optional<CXFA_ViewLayoutProcessor::OverflowData> overflow_data =
           m_pViewLayoutProcessor->ProcessOverflow(pFormNode, true);
       if (overflow_data.has_value()) {
         pOverflowLeaderNode = overflow_data.value().pLeader;
@@ -2653,7 +2653,7 @@
   if (!pFormNode && pLayoutContext)
     pFormNode = pLayoutContext->m_pOverflowProcessor->GetFormNode();
   if (m_pViewLayoutProcessor) {
-    Optional<CXFA_ViewLayoutProcessor::OverflowData> overflow_data =
+    absl::optional<CXFA_ViewLayoutProcessor::OverflowData> overflow_data =
         m_pViewLayoutProcessor->ProcessOverflow(pFormNode, true);
     if (overflow_data.has_value()) {
       pOverflowLeaderNode = overflow_data.value().pLeader;
@@ -2668,7 +2668,7 @@
   return Result::kPageFullBreak;
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::HandleKeep(CXFA_Node* pBreakAfterNode,
                                         CXFA_Node** pCurActionNode) {
   if (m_bKeepBreakFinish)
@@ -2676,7 +2676,7 @@
   return FindBreakNode(pBreakAfterNode, false, pCurActionNode);
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::HandleBookendLeader(CXFA_Node* pParentContainer,
                                                  CXFA_Node** pCurActionNode) {
   for (CXFA_Node* pBookendNode = *pCurActionNode
@@ -2695,7 +2695,7 @@
   return absl::nullopt;
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::HandleBreakBefore(CXFA_Node* pChildContainer,
                                                CXFA_Node** pCurActionNode) {
   if (!*pCurActionNode)
@@ -2703,7 +2703,8 @@
 
   CXFA_Node* pBreakBeforeNode = (*pCurActionNode)->GetNextSibling();
   if (!m_bKeepBreakFinish) {
-    Optional<Stage> ret = FindBreakNode(pBreakBeforeNode, true, pCurActionNode);
+    absl::optional<Stage> ret =
+        FindBreakNode(pBreakBeforeNode, true, pCurActionNode);
     if (ret.has_value())
       return ret.value();
   }
@@ -2714,7 +2715,7 @@
   return Stage::kContainer;
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::HandleBreakAfter(CXFA_Node* pChildContainer,
                                               CXFA_Node** pCurActionNode) {
   if (*pCurActionNode) {
@@ -2726,7 +2727,7 @@
   return HandleKeep(pBreakAfterNode, pCurActionNode);
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::HandleCheckNextChildContainer(
     CXFA_Node* pParentContainer,
     CXFA_Node* pChildContainer,
@@ -2744,7 +2745,7 @@
     return absl::nullopt;
 
   bool bLastKeep = false;
-  Optional<Stage> ret = ProcessKeepNodesForCheckNext(
+  absl::optional<Stage> ret = ProcessKeepNodesForCheckNext(
       pCurActionNode, &pNextChildContainer, &bLastKeep);
   if (ret.has_value())
     return ret.value();
@@ -2759,7 +2760,7 @@
   return m_bIsProcessKeep ? Stage::kKeep : Stage::kContainer;
 }
 
-Optional<CXFA_ContentLayoutProcessor::Stage>
+absl::optional<CXFA_ContentLayoutProcessor::Stage>
 CXFA_ContentLayoutProcessor::HandleBookendTrailer(CXFA_Node* pParentContainer,
                                                   CXFA_Node** pCurActionNode) {
   for (CXFA_Node* pBookendNode = *pCurActionNode
diff --git a/xfa/fxfa/layout/cxfa_contentlayoutprocessor.h b/xfa/fxfa/layout/cxfa_contentlayoutprocessor.h
index f76b9a8..59175c8 100644
--- a/xfa/fxfa/layout/cxfa_contentlayoutprocessor.h
+++ b/xfa/fxfa/layout/cxfa_contentlayoutprocessor.h
@@ -72,7 +72,7 @@
     Context();
     ~Context();
 
-    Optional<float> m_fCurColumnWidth;
+    absl::optional<float> m_fCurColumnWidth;
     UnownedPtr<std::vector<float>> m_prgSpecifiedColumnWidths;
     UnownedPtr<CXFA_ContentLayoutProcessor> m_pOverflowProcessor;  // OK, stack
     UnownedPtr<CXFA_Node> m_pOverflowNode;                         // Ok, stack
@@ -155,12 +155,13 @@
       CXFA_Node* pParentContainer,
       CXFA_Node* pCurActionNode);
 
-  Optional<Stage> ProcessKeepNodesForCheckNext(CXFA_Node** pCurActionNode,
-                                               CXFA_Node** pNextContainer,
-                                               bool* pLastKeepNode);
+  absl::optional<Stage> ProcessKeepNodesForCheckNext(CXFA_Node** pCurActionNode,
+                                                     CXFA_Node** pNextContainer,
+                                                     bool* pLastKeepNode);
 
-  Optional<Stage> ProcessKeepNodesForBreakBefore(CXFA_Node** pCurActionNode,
-                                                 CXFA_Node* pContainerNode);
+  absl::optional<Stage> ProcessKeepNodesForBreakBefore(
+      CXFA_Node** pCurActionNode,
+      CXFA_Node* pContainerNode);
 
   CXFA_Node* GetSubformSetParent(CXFA_Node* pSubformSet);
 
@@ -192,19 +193,20 @@
       Context* pLayoutContext,
       bool bNewRow);
 
-  Optional<Stage> HandleKeep(CXFA_Node* pBreakAfterNode,
-                             CXFA_Node** pCurActionNode);
-  Optional<Stage> HandleBookendLeader(CXFA_Node* pParentContainer,
-                                      CXFA_Node** pCurActionNode);
-  Optional<Stage> HandleBreakBefore(CXFA_Node* pChildContainer,
-                                    CXFA_Node** pCurActionNode);
-  Optional<Stage> HandleBreakAfter(CXFA_Node* pChildContainer,
+  absl::optional<Stage> HandleKeep(CXFA_Node* pBreakAfterNode,
                                    CXFA_Node** pCurActionNode);
-  Optional<Stage> HandleCheckNextChildContainer(CXFA_Node* pParentContainer,
-                                                CXFA_Node* pChildContainer,
-                                                CXFA_Node** pCurActionNode);
-  Optional<Stage> HandleBookendTrailer(CXFA_Node* pParentContainer,
-                                       CXFA_Node** pCurActionNode);
+  absl::optional<Stage> HandleBookendLeader(CXFA_Node* pParentContainer,
+                                            CXFA_Node** pCurActionNode);
+  absl::optional<Stage> HandleBreakBefore(CXFA_Node* pChildContainer,
+                                          CXFA_Node** pCurActionNode);
+  absl::optional<Stage> HandleBreakAfter(CXFA_Node* pChildContainer,
+                                         CXFA_Node** pCurActionNode);
+  absl::optional<Stage> HandleCheckNextChildContainer(
+      CXFA_Node* pParentContainer,
+      CXFA_Node* pChildContainer,
+      CXFA_Node** pCurActionNode);
+  absl::optional<Stage> HandleBookendTrailer(CXFA_Node* pParentContainer,
+                                             CXFA_Node** pCurActionNode);
   void ProcessKeepNodesEnd();
   void AdjustContainerSpecifiedSize(Context* pContext,
                                     CFX_SizeF* pSize,
diff --git a/xfa/fxfa/layout/cxfa_viewlayoutprocessor.cpp b/xfa/fxfa/layout/cxfa_viewlayoutprocessor.cpp
index b6e864c..086e02d 100644
--- a/xfa/fxfa/layout/cxfa_viewlayoutprocessor.cpp
+++ b/xfa/fxfa/layout/cxfa_viewlayoutprocessor.cpp
@@ -185,7 +185,7 @@
   bool bTargetAllFind = true;
   while (iSplitIndex != -1) {
     WideString wsExpr;
-    Optional<size_t> iSplitNextIndex = 0;
+    absl::optional<size_t> iSplitNextIndex = 0;
     if (!bTargetAllFind) {
       iSplitNextIndex = pTargetAll->Find(' ', iSplitIndex);
       if (!iSplitNextIndex.has_value())
@@ -210,7 +210,7 @@
       if (wsExpr.First(4).EqualsASCII("som(") && wsExpr.Back() == L')')
         wsProcessedTarget = wsExpr.Substr(4, wsExpr.GetLength() - 5);
 
-      Optional<CFXJSE_Engine::ResolveResult> maybeResult =
+      absl::optional<CFXJSE_Engine::ResolveResult> maybeResult =
           pDocument->GetScriptContext()->ResolveObjects(
               pPageSetRoot, wsProcessedTarget.AsStringView(),
               Mask<XFA_ResolveFlag>{
@@ -233,7 +233,7 @@
 }
 
 // Note: Returning nullptr is not the same as returning absl::nullopt.
-Optional<CXFA_ViewLayoutItem*> CheckContentAreaNotUsed(
+absl::optional<CXFA_ViewLayoutItem*> CheckContentAreaNotUsed(
     CXFA_ViewLayoutItem* pPageAreaLayoutItem,
     CXFA_Node* pContentArea) {
   for (CXFA_LayoutItem* pChild = pPageAreaLayoutItem->GetFirstChild(); pChild;
@@ -879,17 +879,17 @@
   return ret;
 }
 
-Optional<CXFA_ViewLayoutProcessor::BreakData>
+absl::optional<CXFA_ViewLayoutProcessor::BreakData>
 CXFA_ViewLayoutProcessor::ProcessBreakBefore(const CXFA_Node* pBreakNode) {
   return ProcessBreakBeforeOrAfter(pBreakNode, /*before=*/true);
 }
 
-Optional<CXFA_ViewLayoutProcessor::BreakData>
+absl::optional<CXFA_ViewLayoutProcessor::BreakData>
 CXFA_ViewLayoutProcessor::ProcessBreakAfter(const CXFA_Node* pBreakNode) {
   return ProcessBreakBeforeOrAfter(pBreakNode, /*before=*/false);
 }
 
-Optional<CXFA_ViewLayoutProcessor::BreakData>
+absl::optional<CXFA_ViewLayoutProcessor::BreakData>
 CXFA_ViewLayoutProcessor::ProcessBreakBeforeOrAfter(const CXFA_Node* pBreakNode,
                                                     bool bBefore) {
   CXFA_Node* pFormNode = pBreakNode->GetContainerParent();
@@ -1043,7 +1043,7 @@
   return true;
 }
 
-Optional<CXFA_ViewLayoutProcessor::OverflowData>
+absl::optional<CXFA_ViewLayoutProcessor::OverflowData>
 CXFA_ViewLayoutProcessor::ProcessOverflow(CXFA_Node* pFormNode,
                                           bool bCreatePage) {
   if (!pFormNode)
@@ -1155,7 +1155,7 @@
     CXFA_Node* pOccurNode =
         pPageSet->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
     if (pOccurNode) {
-      Optional<int32_t> ret =
+      absl::optional<int32_t> ret =
           pOccurNode->JSObject()->TryInteger(XFA_Attribute::Max, false);
       if (ret.has_value())
         iMax = ret.value();
@@ -1324,7 +1324,7 @@
   if (m_ePageSetMode != XFA_AttributeValue::DuplexPaginated)
     return true;
 
-  Optional<XFA_AttributeValue> ret =
+  absl::optional<XFA_AttributeValue> ret =
       pPageArea->JSObject()->TryEnum(XFA_Attribute::OddOrEven, true);
   if (!ret.has_value() || ret == XFA_AttributeValue::Any)
     return true;
@@ -1353,7 +1353,7 @@
       CXFA_Node* pOccurNode =
           m_pCurPageArea->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
       if (pOccurNode) {
-        Optional<int32_t> ret =
+        absl::optional<int32_t> ret =
             pOccurNode->JSObject()->TryInteger(XFA_Attribute::Max, false);
         if (ret.has_value())
           iMax = ret.value();
@@ -1415,8 +1415,9 @@
     if (pContentArea->GetParent() != m_pCurPageArea)
       return false;
 
-    Optional<CXFA_ViewLayoutItem*> pContentAreaLayout = CheckContentAreaNotUsed(
-        GetCurrentViewRecord()->pCurPageArea.Get(), pContentArea);
+    absl::optional<CXFA_ViewLayoutItem*> pContentAreaLayout =
+        CheckContentAreaNotUsed(GetCurrentViewRecord()->pCurPageArea.Get(),
+                                pContentArea);
     if (!pContentAreaLayout.has_value())
       return false;
     if (pContentAreaLayout.value()) {
@@ -1457,7 +1458,7 @@
     return 0;
 
   int32_t iMin = 0;
-  Optional<int32_t> ret;
+  absl::optional<int32_t> ret;
   CXFA_Node* pOccurNode =
       pPageArea->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
   if (pOccurNode) {
@@ -1501,7 +1502,7 @@
   if (!pOccurNode)
     return;
 
-  Optional<int32_t> iMin =
+  absl::optional<int32_t> iMin =
       pOccurNode->JSObject()->TryInteger(XFA_Attribute::Min, false);
   if (!iMin.has_value() || iCurSetCount >= iMin.value())
     return;
@@ -1566,7 +1567,7 @@
   CXFA_Node* pOccurNode =
       pPageNode->GetFirstChildByClass<CXFA_Occur>(XFA_Element::Occur);
   int32_t iMax = 0;
-  Optional<int32_t> ret;
+  absl::optional<int32_t> ret;
   if (pOccurNode) {
     ret = pOccurNode->JSObject()->TryInteger(XFA_Attribute::Max, false);
     if (ret.has_value())
diff --git a/xfa/fxfa/layout/cxfa_viewlayoutprocessor.h b/xfa/fxfa/layout/cxfa_viewlayoutprocessor.h
index 59529b0..526b7aa 100644
--- a/xfa/fxfa/layout/cxfa_viewlayoutprocessor.h
+++ b/xfa/fxfa/layout/cxfa_viewlayoutprocessor.h
@@ -62,10 +62,10 @@
   CXFA_ViewLayoutItem* GetRootLayoutItem() const {
     return m_pPageSetRootLayoutItem.Get();
   }
-  Optional<BreakData> ProcessBreakBefore(const CXFA_Node* pBreakNode);
-  Optional<BreakData> ProcessBreakAfter(const CXFA_Node* pBreakNode);
-  Optional<OverflowData> ProcessOverflow(CXFA_Node* pFormNode,
-                                         bool bCreatePage);
+  absl::optional<BreakData> ProcessBreakBefore(const CXFA_Node* pBreakNode);
+  absl::optional<BreakData> ProcessBreakAfter(const CXFA_Node* pBreakNode);
+  absl::optional<OverflowData> ProcessOverflow(CXFA_Node* pFormNode,
+                                               bool bCreatePage);
   CXFA_Node* QueryOverflow(CXFA_Node* pFormNode);
   CXFA_Node* ProcessBookendLeader(const CXFA_Node* pBookendNode);
   CXFA_Node* ProcessBookendTrailer(const CXFA_Node* pBookendNode);
@@ -130,8 +130,9 @@
                                            bool bLeader);
   CXFA_Node* ResolveBookendLeaderOrTrailer(const CXFA_Node* pBookendNode,
                                            bool bLeader);
-  Optional<BreakData> ProcessBreakBeforeOrAfter(const CXFA_Node* pBreakNode,
-                                                bool bBefore);
+  absl::optional<BreakData> ProcessBreakBeforeOrAfter(
+      const CXFA_Node* pBreakNode,
+      bool bBefore);
   BreakData ExecuteBreakBeforeOrAfter(const CXFA_Node* pCurNode, bool bBefore);
 
   int32_t CreateMinPageRecord(CXFA_Node* pPageArea,
diff --git a/xfa/fxfa/parser/cxfa_barcode.cpp b/xfa/fxfa/parser/cxfa_barcode.cpp
index dd1efba..0b3636f 100644
--- a/xfa/fxfa/parser/cxfa_barcode.cpp
+++ b/xfa/fxfa/parser/cxfa_barcode.cpp
@@ -64,12 +64,12 @@
   return WideString(JSObject()->GetCData(XFA_Attribute::Type));
 }
 
-Optional<WideString> CXFA_Barcode::GetCharEncoding() {
+absl::optional<WideString> CXFA_Barcode::GetCharEncoding() {
   return JSObject()->TryCData(XFA_Attribute::CharEncoding, true);
 }
 
-Optional<bool> CXFA_Barcode::GetChecksum() {
-  Optional<XFA_AttributeValue> checksum =
+absl::optional<bool> CXFA_Barcode::GetChecksum() {
+  absl::optional<XFA_AttributeValue> checksum =
       JSObject()->TryEnum(XFA_Attribute::Checksum, true);
   if (!checksum.has_value())
     return absl::nullopt;
@@ -88,8 +88,8 @@
   return absl::nullopt;
 }
 
-Optional<int32_t> CXFA_Barcode::GetDataLength() {
-  Optional<WideString> wsDataLength =
+absl::optional<int32_t> CXFA_Barcode::GetDataLength() {
+  absl::optional<WideString> wsDataLength =
       JSObject()->TryCData(XFA_Attribute::DataLength, true);
   if (!wsDataLength.has_value())
     return absl::nullopt;
@@ -97,8 +97,8 @@
   return FXSYS_wtoi(wsDataLength->c_str());
 }
 
-Optional<char> CXFA_Barcode::GetStartChar() {
-  Optional<WideString> wsStartEndChar =
+absl::optional<char> CXFA_Barcode::GetStartChar() {
+  absl::optional<WideString> wsStartEndChar =
       JSObject()->TryCData(XFA_Attribute::StartChar, true);
   if (!wsStartEndChar.has_value() || wsStartEndChar->IsEmpty())
     return absl::nullopt;
@@ -106,8 +106,8 @@
   return static_cast<char>(wsStartEndChar.value()[0]);
 }
 
-Optional<char> CXFA_Barcode::GetEndChar() {
-  Optional<WideString> wsStartEndChar =
+absl::optional<char> CXFA_Barcode::GetEndChar() {
+  absl::optional<WideString> wsStartEndChar =
       JSObject()->TryCData(XFA_Attribute::EndChar, true);
   if (!wsStartEndChar.has_value() || wsStartEndChar->IsEmpty())
     return absl::nullopt;
@@ -115,16 +115,16 @@
   return static_cast<char>(wsStartEndChar.value()[0]);
 }
 
-Optional<int32_t> CXFA_Barcode::GetECLevel() {
-  Optional<WideString> wsECLevel =
+absl::optional<int32_t> CXFA_Barcode::GetECLevel() {
+  absl::optional<WideString> wsECLevel =
       JSObject()->TryCData(XFA_Attribute::ErrorCorrectionLevel, true);
   if (!wsECLevel.has_value())
     return absl::nullopt;
   return FXSYS_wtoi(wsECLevel->c_str());
 }
 
-Optional<int32_t> CXFA_Barcode::GetModuleWidth() {
-  Optional<CXFA_Measurement> moduleWidthHeight =
+absl::optional<int32_t> CXFA_Barcode::GetModuleWidth() {
+  absl::optional<CXFA_Measurement> moduleWidthHeight =
       JSObject()->TryMeasure(XFA_Attribute::ModuleWidth, true);
   if (!moduleWidthHeight.has_value())
     return absl::nullopt;
@@ -132,8 +132,8 @@
   return static_cast<int32_t>(moduleWidthHeight->ToUnit(XFA_Unit::Pt));
 }
 
-Optional<int32_t> CXFA_Barcode::GetModuleHeight() {
-  Optional<CXFA_Measurement> moduleWidthHeight =
+absl::optional<int32_t> CXFA_Barcode::GetModuleHeight() {
+  absl::optional<CXFA_Measurement> moduleWidthHeight =
       JSObject()->TryMeasure(XFA_Attribute::ModuleHeight, true);
   if (!moduleWidthHeight.has_value())
     return absl::nullopt;
@@ -141,25 +141,25 @@
   return static_cast<int32_t>(moduleWidthHeight->ToUnit(XFA_Unit::Pt));
 }
 
-Optional<bool> CXFA_Barcode::GetPrintChecksum() {
+absl::optional<bool> CXFA_Barcode::GetPrintChecksum() {
   return JSObject()->TryBoolean(XFA_Attribute::PrintCheckDigit, true);
 }
 
-Optional<XFA_AttributeValue> CXFA_Barcode::GetTextLocation() {
+absl::optional<XFA_AttributeValue> CXFA_Barcode::GetTextLocation() {
   return JSObject()->TryEnum(XFA_Attribute::TextLocation, true);
 }
 
-Optional<bool> CXFA_Barcode::GetTruncate() {
+absl::optional<bool> CXFA_Barcode::GetTruncate() {
   return JSObject()->TryBoolean(XFA_Attribute::Truncate, true);
 }
 
-Optional<int8_t> CXFA_Barcode::GetWideNarrowRatio() {
-  Optional<WideString> wsWideNarrowRatio =
+absl::optional<int8_t> CXFA_Barcode::GetWideNarrowRatio() {
+  absl::optional<WideString> wsWideNarrowRatio =
       JSObject()->TryCData(XFA_Attribute::WideNarrowRatio, true);
   if (!wsWideNarrowRatio.has_value())
     return absl::nullopt;
 
-  Optional<size_t> ptPos = wsWideNarrowRatio->Find(':');
+  absl::optional<size_t> ptPos = wsWideNarrowRatio->Find(':');
   if (!ptPos.has_value())
     return static_cast<int8_t>(FXSYS_wtoi(wsWideNarrowRatio->c_str()));
 
diff --git a/xfa/fxfa/parser/cxfa_barcode.h b/xfa/fxfa/parser/cxfa_barcode.h
index 520e5d1..1ae6d08 100644
--- a/xfa/fxfa/parser/cxfa_barcode.h
+++ b/xfa/fxfa/parser/cxfa_barcode.h
@@ -18,18 +18,18 @@
   XFA_FFWidgetType GetDefaultFFWidgetType() const override;
 
   WideString GetBarcodeType();
-  Optional<WideString> GetCharEncoding();
-  Optional<bool> GetChecksum();
-  Optional<int32_t> GetDataLength();
-  Optional<char> GetStartChar();
-  Optional<char> GetEndChar();
-  Optional<int32_t> GetECLevel();
-  Optional<int32_t> GetModuleWidth();
-  Optional<int32_t> GetModuleHeight();
-  Optional<bool> GetPrintChecksum();
-  Optional<XFA_AttributeValue> GetTextLocation();
-  Optional<bool> GetTruncate();
-  Optional<int8_t> GetWideNarrowRatio();
+  absl::optional<WideString> GetCharEncoding();
+  absl::optional<bool> GetChecksum();
+  absl::optional<int32_t> GetDataLength();
+  absl::optional<char> GetStartChar();
+  absl::optional<char> GetEndChar();
+  absl::optional<int32_t> GetECLevel();
+  absl::optional<int32_t> GetModuleWidth();
+  absl::optional<int32_t> GetModuleHeight();
+  absl::optional<bool> GetPrintChecksum();
+  absl::optional<XFA_AttributeValue> GetTextLocation();
+  absl::optional<bool> GetTruncate();
+  absl::optional<int8_t> GetWideNarrowRatio();
 
  private:
   CXFA_Barcode(CXFA_Document* doc, XFA_PacketType packet);
diff --git a/xfa/fxfa/parser/cxfa_box.cpp b/xfa/fxfa/parser/cxfa_box.cpp
index 40a85c7..4ab2519 100644
--- a/xfa/fxfa/parser/cxfa_box.cpp
+++ b/xfa/fxfa/parser/cxfa_box.cpp
@@ -108,11 +108,11 @@
   return JSObject()->GetBoolean(XFA_Attribute::Circular);
 }
 
-Optional<int32_t> CXFA_Box::GetStartAngle() {
+absl::optional<int32_t> CXFA_Box::GetStartAngle() {
   return JSObject()->TryInteger(XFA_Attribute::StartAngle, false);
 }
 
-Optional<int32_t> CXFA_Box::GetSweepAngle() {
+absl::optional<int32_t> CXFA_Box::GetSweepAngle() {
   return JSObject()->TryInteger(XFA_Attribute::SweepAngle, false);
 }
 
@@ -256,8 +256,8 @@
   rtDraw.top = center.y - b;
   rtDraw.width = a + a;
   rtDraw.height = b + b;
-  Optional<int32_t> startAngle = GetStartAngle();
-  Optional<int32_t> sweepAngle = GetSweepAngle();
+  absl::optional<int32_t> startAngle = GetStartAngle();
+  absl::optional<int32_t> sweepAngle = GetSweepAngle();
   if (!startAngle.has_value() && !sweepAngle.has_value()) {
     fillPath->AddEllipse(rtDraw);
     return;
diff --git a/xfa/fxfa/parser/cxfa_box.h b/xfa/fxfa/parser/cxfa_box.h
index 0c12ada..c4d00e1 100644
--- a/xfa/fxfa/parser/cxfa_box.h
+++ b/xfa/fxfa/parser/cxfa_box.h
@@ -52,8 +52,8 @@
 
  private:
   bool IsCircular();
-  Optional<int32_t> GetStartAngle();
-  Optional<int32_t> GetSweepAngle();
+  absl::optional<int32_t> GetStartAngle();
+  absl::optional<int32_t> GetSweepAngle();
 
   std::vector<CXFA_Stroke*> GetStrokesInternal(bool bNull);
   void DrawFill(const std::vector<CXFA_Stroke*>& strokes,
diff --git a/xfa/fxfa/parser/cxfa_color.cpp b/xfa/fxfa/parser/cxfa_color.cpp
index d16f14d..74d9c07 100644
--- a/xfa/fxfa/parser/cxfa_color.cpp
+++ b/xfa/fxfa/parser/cxfa_color.cpp
@@ -95,12 +95,14 @@
 CXFA_Color::~CXFA_Color() = default;
 
 FX_ARGB CXFA_Color::GetValue() const {
-  Optional<WideString> val = JSObject()->TryCData(XFA_Attribute::Value, false);
+  absl::optional<WideString> val =
+      JSObject()->TryCData(XFA_Attribute::Value, false);
   return val.has_value() ? StringToFXARGB(val->AsStringView()) : 0xFF000000;
 }
 
 FX_ARGB CXFA_Color::GetValueOrDefault(FX_ARGB defaultValue) const {
-  Optional<WideString> val = JSObject()->TryCData(XFA_Attribute::Value, false);
+  absl::optional<WideString> val =
+      JSObject()->TryCData(XFA_Attribute::Value, false);
   return val.has_value() ? StringToFXARGB(val->AsStringView()) : defaultValue;
 }
 
diff --git a/xfa/fxfa/parser/cxfa_document.cpp b/xfa/fxfa/parser/cxfa_document.cpp
index 484ad2b..634daec 100644
--- a/xfa/fxfa/parser/cxfa_document.cpp
+++ b/xfa/fxfa/parser/cxfa_document.cpp
@@ -106,7 +106,7 @@
       if (!pContentRawDataNode) {
         XFA_Element element = XFA_Element::Sharptext;
         if (pChildNode->GetElementType() == XFA_Element::ExData) {
-          Optional<WideString> contentType =
+          absl::optional<WideString> contentType =
               pChildNode->JSObject()->TryAttribute(XFA_Attribute::ContentType,
                                                    false);
           if (contentType.has_value()) {
@@ -352,7 +352,7 @@
     dwFlags |= XFA_ResolveFlag::kParent;
     dwFlags |= XFA_ResolveFlag::kSiblings;
   }
-  Optional<CFXJSE_Engine::ResolveResult> maybeResult =
+  absl::optional<CFXJSE_Engine::ResolveResult> maybeResult =
       pDocument->GetScriptContext()->ResolveObjectsWithBindNode(
           pDataScope, wsRef.AsStringView(), dwFlags, pTemplateNode);
   if (!maybeResult.has_value())
@@ -752,7 +752,7 @@
       if (pDDGroupNode->GetElementType() != XFA_Element::DataGroup)
         continue;
 
-      Optional<WideString> ns = pDDGroupNode->JSObject()->TryNamespace();
+      absl::optional<WideString> ns = pDDGroupNode->JSObject()->TryNamespace();
       if (!ns.has_value() ||
           !ns.value().EqualsASCII("http://ns.adobe.com/data-description/")) {
         continue;
@@ -1201,7 +1201,7 @@
                   : WideString();
           const Mask<XFA_ResolveFlag> kFlags = {XFA_ResolveFlag::kChildren,
                                                 XFA_ResolveFlag::kCreateNode};
-          Optional<CFXJSE_Engine::ResolveResult> maybeResult =
+          absl::optional<CFXJSE_Engine::ResolveResult> maybeResult =
               pDocument->GetScriptContext()->ResolveObjectsWithBindNode(
                   pDataScope, wsRef.AsStringView(), kFlags, pTemplateNode);
           CXFA_Object* pObject =
@@ -1259,7 +1259,8 @@
         if (pDDGroupNode->GetElementType() != XFA_Element::DataGroup)
           continue;
 
-        Optional<WideString> ns = pDDGroupNode->JSObject()->TryNamespace();
+        absl::optional<WideString> ns =
+            pDDGroupNode->JSObject()->TryNamespace();
         if (!ns.has_value() ||
             !ns.value().EqualsASCII("http://ns.adobe.com/data-description/")) {
           continue;
@@ -1340,12 +1341,12 @@
         if (pDatasetsChild->GetNameHash() != XFA_HASHCODE_Data)
           continue;
 
-        Optional<WideString> namespaceURI =
+        absl::optional<WideString> namespaceURI =
             pDatasetsChild->JSObject()->TryNamespace();
         if (!namespaceURI.has_value())
           continue;
 
-        Optional<WideString> datasetsURI =
+        absl::optional<WideString> datasetsURI =
             pDatasetsNode->JSObject()->TryNamespace();
         if (!datasetsURI.has_value())
           continue;
@@ -1578,7 +1579,7 @@
 
     CXFA_Node* pProtoNode = nullptr;
     if (!wsSOM.IsEmpty()) {
-      Optional<CFXJSE_Engine::ResolveResult> maybeResult =
+      absl::optional<CFXJSE_Engine::ResolveResult> maybeResult =
           m_pScriptContext->ResolveObjects(
               pUseHrefNode, wsSOM,
               Mask<XFA_ResolveFlag>{
@@ -1681,7 +1682,7 @@
       continue;
 
     if (!pDDRoot && pChildNode->GetNameHash() == XFA_HASHCODE_DataDescription) {
-      Optional<WideString> namespaceURI =
+      absl::optional<WideString> namespaceURI =
           pChildNode->JSObject()->TryNamespace();
       if (!namespaceURI.has_value())
         continue;
@@ -1690,7 +1691,7 @@
         pDDRoot = pChildNode;
       }
     } else if (!pDataRoot && pChildNode->GetNameHash() == XFA_HASHCODE_Data) {
-      Optional<WideString> namespaceURI =
+      absl::optional<WideString> namespaceURI =
           pChildNode->JSObject()->TryNamespace();
       if (!namespaceURI.has_value())
         continue;
diff --git a/xfa/fxfa/parser/cxfa_document.h b/xfa/fxfa/parser/cxfa_document.h
index bbada2d..677e9d1 100644
--- a/xfa/fxfa/parser/cxfa_document.h
+++ b/xfa/fxfa/parser/cxfa_document.h
@@ -165,7 +165,7 @@
   std::map<uint32_t, cppgc::Member<CXFA_Node>> m_rgGlobalBinding;
   std::vector<cppgc::Member<CXFA_Node>> m_pPendingPageSet;
   XFA_VERSION m_eCurVersionMode = XFA_VERSION_DEFAULT;
-  Optional<bool> m_Interactive;
+  absl::optional<bool> m_Interactive;
   bool m_bStrictScoping = false;
   bool m_bScripting = false;
 };
diff --git a/xfa/fxfa/parser/cxfa_document_builder.cpp b/xfa/fxfa/parser/cxfa_document_builder.cpp
index db4bdbc..24f666d 100644
--- a/xfa/fxfa/parser/cxfa_document_builder.cpp
+++ b/xfa/fxfa/parser/cxfa_document_builder.cpp
@@ -98,9 +98,10 @@
   return true;
 }
 
-Optional<WideString> FindAttributeWithNS(CFX_XMLElement* pElement,
-                                         WideStringView wsLocalAttributeName,
-                                         WideStringView wsNamespaceURIPrefix) {
+absl::optional<WideString> FindAttributeWithNS(
+    CFX_XMLElement* pElement,
+    WideStringView wsLocalAttributeName,
+    WideStringView wsNamespaceURIPrefix) {
   WideString wsAttrNS;
   for (auto it : pElement->GetAttributes()) {
     auto pos = it.first.Find(L':', 0);
@@ -377,7 +378,7 @@
       continue;
 
     WideString wsPacketName = pElement->GetLocalTagName();
-    Optional<XFA_PACKETINFO> packet_info =
+    absl::optional<XFA_PACKETINFO> packet_info =
         XFA_GetPacketByName(wsPacketName.AsStringView());
     if (packet_info.has_value() && packet_info.value().uri &&
         !MatchNodeName(pElement, packet_info.value().name,
@@ -677,7 +678,7 @@
           if (wsAttrName.EqualsASCII("nil") && it.second.EqualsASCII("true"))
             IsNeedValue = false;
 
-          Optional<XFA_ATTRIBUTEINFO> attr =
+          absl::optional<XFA_ATTRIBUTEINFO> attr =
               XFA_GetAttributeByName(wsAttrName.AsStringView());
           if (!attr.has_value())
             continue;
@@ -795,7 +796,7 @@
 
         XFA_Element eNodeType = XFA_Element::DataModel;
         if (eNodeType == XFA_Element::DataModel) {
-          Optional<WideString> wsDataNodeAttr =
+          absl::optional<WideString> wsDataNodeAttr =
               FindAttributeWithNS(pXMLElement, L"dataNode",
                                   L"http://www.xfa.org/schema/xfa-data/1.0/");
           if (wsDataNodeAttr.has_value()) {
@@ -806,7 +807,7 @@
           }
         }
         if (eNodeType == XFA_Element::DataModel) {
-          Optional<WideString> wsContentType =
+          absl::optional<WideString> wsContentType =
               FindAttributeWithNS(pXMLElement, L"contentType",
                                   L"http://www.xfa.org/schema/xfa-data/1.0/");
           if (wsContentType.has_value() && !wsContentType.value().IsEmpty())
diff --git a/xfa/fxfa/parser/cxfa_localemgr.cpp b/xfa/fxfa/parser/cxfa_localemgr.cpp
index 3e92d0d..74cd665 100644
--- a/xfa/fxfa/parser/cxfa_localemgr.cpp
+++ b/xfa/fxfa/parser/cxfa_localemgr.cpp
@@ -1232,7 +1232,7 @@
   m_pDefLocale = pLocale;
 }
 
-Optional<WideString> CXFA_LocaleMgr::GetConfigLocaleName(
+absl::optional<WideString> CXFA_LocaleMgr::GetConfigLocaleName(
     CXFA_Node* pConfig) const {
   if (m_bConfigLocaleCached)
     return m_wsConfigLocale;
@@ -1261,7 +1261,7 @@
   if (!pLocale)
     return m_wsConfigLocale;
 
-  Optional<WideString> wsMaybeLocale =
+  absl::optional<WideString> wsMaybeLocale =
       pLocale->JSObject()->TryCData(XFA_Attribute::Value, false);
   if (!wsMaybeLocale.has_value() || wsMaybeLocale.value().IsEmpty())
     return m_wsConfigLocale;
diff --git a/xfa/fxfa/parser/cxfa_localemgr.h b/xfa/fxfa/parser/cxfa_localemgr.h
index d5d97b6..596cbe5 100644
--- a/xfa/fxfa/parser/cxfa_localemgr.h
+++ b/xfa/fxfa/parser/cxfa_localemgr.h
@@ -52,7 +52,7 @@
   GCedLocaleIface* GetLocaleByName(const WideString& wsLocaleName) override;
 
   void SetDefLocale(GCedLocaleIface* pLocale);
-  Optional<WideString> GetConfigLocaleName(CXFA_Node* pConfig) const;
+  absl::optional<WideString> GetConfigLocaleName(CXFA_Node* pConfig) const;
 
  private:
   CXFA_LocaleMgr(cppgc::Heap* pHeap,
@@ -74,7 +74,7 @@
   // 3. we might have tried and gotten something.
   // So |m_bConfigLocaleCached| indicates whether we've already tried,
   // and |m_wsConfigLocale| is the possibly nothing we got if we tried.
-  mutable Optional<WideString> m_wsConfigLocale;
+  mutable absl::optional<WideString> m_wsConfigLocale;
   mutable bool m_bConfigLocaleCached = false;
 
   LangID m_eDeflcid;
diff --git a/xfa/fxfa/parser/cxfa_margin.cpp b/xfa/fxfa/parser/cxfa_margin.cpp
index aff9cd4..eec2aef 100644
--- a/xfa/fxfa/parser/cxfa_margin.cpp
+++ b/xfa/fxfa/parser/cxfa_margin.cpp
@@ -57,18 +57,18 @@
   return TryBottomInset().value_or(0);
 }
 
-Optional<float> CXFA_Margin::TryLeftInset() const {
+absl::optional<float> CXFA_Margin::TryLeftInset() const {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::LeftInset);
 }
 
-Optional<float> CXFA_Margin::TryTopInset() const {
+absl::optional<float> CXFA_Margin::TryTopInset() const {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::TopInset);
 }
 
-Optional<float> CXFA_Margin::TryRightInset() const {
+absl::optional<float> CXFA_Margin::TryRightInset() const {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::RightInset);
 }
 
-Optional<float> CXFA_Margin::TryBottomInset() const {
+absl::optional<float> CXFA_Margin::TryBottomInset() const {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::BottomInset);
 }
diff --git a/xfa/fxfa/parser/cxfa_margin.h b/xfa/fxfa/parser/cxfa_margin.h
index bb32da9..24b0174 100644
--- a/xfa/fxfa/parser/cxfa_margin.h
+++ b/xfa/fxfa/parser/cxfa_margin.h
@@ -19,10 +19,10 @@
   float GetRightInset() const;
   float GetBottomInset() const;
 
-  Optional<float> TryLeftInset() const;
-  Optional<float> TryTopInset() const;
-  Optional<float> TryRightInset() const;
-  Optional<float> TryBottomInset() const;
+  absl::optional<float> TryLeftInset() const;
+  absl::optional<float> TryTopInset() const;
+  absl::optional<float> TryRightInset() const;
+  absl::optional<float> TryBottomInset() const;
 
  private:
   CXFA_Margin(CXFA_Document* doc, XFA_PacketType packet);
diff --git a/xfa/fxfa/parser/cxfa_node.cpp b/xfa/fxfa/parser/cxfa_node.cpp
index 64cb174..64bb803 100644
--- a/xfa/fxfa/parser/cxfa_node.cpp
+++ b/xfa/fxfa/parser/cxfa_node.cpp
@@ -1156,7 +1156,7 @@
   return pNewNode;
 }
 
-Optional<XFA_Element> CXFA_Node::GetFirstPropertyWithFlag(
+absl::optional<XFA_Element> CXFA_Node::GetFirstPropertyWithFlag(
     XFA_PropertyFlag flag) const {
   for (const auto& prop : m_Properties) {
     if (prop.flags & flag)
@@ -1240,7 +1240,7 @@
   if (!bFilterOneOfProperties || !nodes.empty())
     return nodes;
 
-  Optional<XFA_Element> property =
+  absl::optional<XFA_Element> property =
       GetFirstPropertyWithFlag(XFA_PropertyFlag::kDefaultOneOf);
   if (!property.has_value())
     return nodes;
@@ -1405,7 +1405,7 @@
 }
 
 GCedLocaleIface* CXFA_Node::GetLocale() {
-  Optional<WideString> localeName = GetLocaleName();
+  absl::optional<WideString> localeName = GetLocaleName();
   if (!localeName.has_value())
     return nullptr;
   if (localeName.value().EqualsASCII("ambient"))
@@ -1413,7 +1413,7 @@
   return GetDocument()->GetLocaleMgr()->GetLocaleByName(localeName.value());
 }
 
-Optional<WideString> CXFA_Node::GetLocaleName() {
+absl::optional<WideString> CXFA_Node::GetLocaleName() {
   CXFA_Node* pForm = ToNode(GetDocument()->GetXFAObject(XFA_HASHCODE_Form));
   if (!pForm)
     return absl::nullopt;
@@ -1423,7 +1423,7 @@
   if (!pTopSubform)
     return absl::nullopt;
 
-  Optional<WideString> localeName;
+  absl::optional<WideString> localeName;
   CXFA_Node* pLocaleNode = this;
   do {
     localeName =
@@ -1459,7 +1459,8 @@
   XFA_AttributeValue eLayoutType =
       layout.value_or(XFA_AttributeValue::Position);
   if (pKeep) {
-    Optional<XFA_AttributeValue> intact = GetIntactFromKeep(pKeep, eLayoutType);
+    absl::optional<XFA_AttributeValue> intact =
+        GetIntactFromKeep(pKeep, eLayoutType);
     if (intact.has_value())
       return intact.value();
   }
@@ -1491,7 +1492,7 @@
 
       XFA_VERSION version = m_pDocument->GetCurVersionMode();
       if (eParLayout == XFA_AttributeValue::Tb && version < XFA_VERSION_208) {
-        Optional<CXFA_Measurement> measureH =
+        absl::optional<CXFA_Measurement> measureH =
             JSObject()->TryMeasure(XFA_Attribute::H, false);
         if (measureH.has_value())
           return XFA_AttributeValue::ContentArea;
@@ -2032,23 +2033,26 @@
   return pInstance;
 }
 
-Optional<bool> CXFA_Node::GetDefaultBoolean(XFA_Attribute attr) const {
-  Optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::Boolean);
+absl::optional<bool> CXFA_Node::GetDefaultBoolean(XFA_Attribute attr) const {
+  absl::optional<void*> value =
+      GetDefaultValue(attr, XFA_AttributeType::Boolean);
   if (!value.has_value())
     return absl::nullopt;
   return !!value.value();
 }
 
-Optional<int32_t> CXFA_Node::GetDefaultInteger(XFA_Attribute attr) const {
-  Optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::Integer);
+absl::optional<int32_t> CXFA_Node::GetDefaultInteger(XFA_Attribute attr) const {
+  absl::optional<void*> value =
+      GetDefaultValue(attr, XFA_AttributeType::Integer);
   if (!value.has_value())
     return absl::nullopt;
   return static_cast<int32_t>(reinterpret_cast<uintptr_t>(value.value()));
 }
 
-Optional<CXFA_Measurement> CXFA_Node::GetDefaultMeasurement(
+absl::optional<CXFA_Measurement> CXFA_Node::GetDefaultMeasurement(
     XFA_Attribute attr) const {
-  Optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::Measure);
+  absl::optional<void*> value =
+      GetDefaultValue(attr, XFA_AttributeType::Measure);
   if (!value.has_value())
     return absl::nullopt;
 
@@ -2056,25 +2060,27 @@
   return CXFA_Measurement(str.AsStringView());
 }
 
-Optional<WideString> CXFA_Node::GetDefaultCData(XFA_Attribute attr) const {
-  Optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::CData);
+absl::optional<WideString> CXFA_Node::GetDefaultCData(
+    XFA_Attribute attr) const {
+  absl::optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::CData);
   if (!value.has_value())
     return absl::nullopt;
 
   return WideString(static_cast<const wchar_t*>(value.value()));
 }
 
-Optional<XFA_AttributeValue> CXFA_Node::GetDefaultEnum(
+absl::optional<XFA_AttributeValue> CXFA_Node::GetDefaultEnum(
     XFA_Attribute attr) const {
-  Optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::Enum);
+  absl::optional<void*> value = GetDefaultValue(attr, XFA_AttributeType::Enum);
   if (!value.has_value())
     return absl::nullopt;
   return static_cast<XFA_AttributeValue>(
       reinterpret_cast<uintptr_t>(value.value()));
 }
 
-Optional<void*> CXFA_Node::GetDefaultValue(XFA_Attribute attr,
-                                           XFA_AttributeType eType) const {
+absl::optional<void*> CXFA_Node::GetDefaultValue(
+    XFA_Attribute attr,
+    XFA_AttributeType eType) const {
   const AttributeData* data = GetAttributeData(attr);
   if (!data || data->type != eType)
     return absl::nullopt;
@@ -2242,7 +2248,7 @@
 }
 
 int32_t CXFA_Node::GetRotate() const {
-  Optional<int32_t> degrees =
+  absl::optional<int32_t> degrees =
       JSObject()->TryInteger(XFA_Attribute::Rotate, false);
   return degrees.has_value() ? XFA_MapRotation(degrees.value()) / 90 * 90 : 0;
 }
@@ -2334,10 +2340,10 @@
   return JSObject()->GetProperty<CXFA_Bind>(0, XFA_Element::Bind);
 }
 
-Optional<XFA_AttributeValue> CXFA_Node::GetIntactFromKeep(
+absl::optional<XFA_AttributeValue> CXFA_Node::GetIntactFromKeep(
     const CXFA_Keep* pKeep,
     XFA_AttributeValue eLayoutType) const {
-  Optional<XFA_AttributeValue> intact =
+  absl::optional<XFA_AttributeValue> intact =
       pKeep->JSObject()->TryEnum(XFA_Attribute::Intact, false);
   if (!intact.has_value())
     return absl::nullopt;
@@ -2354,7 +2360,7 @@
     return intact;
   }
 
-  Optional<XFA_AttributeValue> value =
+  absl::optional<XFA_AttributeValue> value =
       pKeep->JSObject()->TryEnum(XFA_Attribute::Previous, false);
   if (value == XFA_AttributeValue::ContentArea ||
       value == XFA_AttributeValue::PageArea) {
@@ -2366,7 +2372,7 @@
   if (!pNode)
     return intact;
 
-  Optional<XFA_AttributeValue> ret =
+  absl::optional<XFA_AttributeValue> ret =
       pNode->JSObject()->TryEnum(XFA_Attribute::Next, false);
   if (ret == XFA_AttributeValue::ContentArea ||
       ret == XFA_AttributeValue::PageArea) {
@@ -2375,27 +2381,27 @@
   return intact;
 }
 
-Optional<float> CXFA_Node::TryWidth() {
+absl::optional<float> CXFA_Node::TryWidth() {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::W);
 }
 
-Optional<float> CXFA_Node::TryHeight() {
+absl::optional<float> CXFA_Node::TryHeight() {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::H);
 }
 
-Optional<float> CXFA_Node::TryMinWidth() {
+absl::optional<float> CXFA_Node::TryMinWidth() {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::MinW);
 }
 
-Optional<float> CXFA_Node::TryMinHeight() {
+absl::optional<float> CXFA_Node::TryMinHeight() {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::MinH);
 }
 
-Optional<float> CXFA_Node::TryMaxWidth() {
+absl::optional<float> CXFA_Node::TryMaxWidth() {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::MaxW);
 }
 
-Optional<float> CXFA_Node::TryMaxHeight() {
+absl::optional<float> CXFA_Node::TryMaxHeight() {
   return JSObject()->TryMeasureAsFloat(XFA_Attribute::MaxH);
 }
 
@@ -2996,10 +3002,10 @@
   if (border && border->GetPresence() != XFA_AttributeValue::Visible)
     return CFX_RectF();
 
-  Optional<float> left = mgUI->TryLeftInset();
-  Optional<float> top = mgUI->TryTopInset();
-  Optional<float> right = mgUI->TryRightInset();
-  Optional<float> bottom = mgUI->TryBottomInset();
+  absl::optional<float> left = mgUI->TryLeftInset();
+  absl::optional<float> top = mgUI->TryTopInset();
+  absl::optional<float> right = mgUI->TryRightInset();
+  absl::optional<float> bottom = mgUI->TryBottomInset();
   if (border) {
     bool bVisible = false;
     float fThickness = 0;
@@ -3243,28 +3249,28 @@
   if (para)
     pSize->width += para->GetMarginLeft() + para->GetTextIndent();
 
-  Optional<float> width = TryWidth();
+  absl::optional<float> width = TryWidth();
   if (width.has_value()) {
     pSize->width = width.value();
   } else {
-    Optional<float> min = TryMinWidth();
+    absl::optional<float> min = TryMinWidth();
     if (min.has_value())
       pSize->width = std::max(pSize->width, min.value());
 
-    Optional<float> max = TryMaxWidth();
+    absl::optional<float> max = TryMaxWidth();
     if (max.has_value() && max.value() > 0)
       pSize->width = std::min(pSize->width, max.value());
   }
 
-  Optional<float> height = TryHeight();
+  absl::optional<float> height = TryHeight();
   if (height.has_value()) {
     pSize->height = height.value();
   } else {
-    Optional<float> min = TryMinHeight();
+    absl::optional<float> min = TryMinHeight();
     if (min.has_value())
       pSize->height = std::max(pSize->height, min.value());
 
-    Optional<float> max = TryMaxHeight();
+    absl::optional<float> max = TryMaxHeight();
     if (max.has_value() && max.value() > 0)
       pSize->height = std::min(pSize->height, max.value());
   }
@@ -3373,7 +3379,7 @@
                     XFA_UnitPx2Pt(img_height, dpi.height));
 
   CFX_RectF rtFit;
-  Optional<float> width = TryWidth();
+  absl::optional<float> width = TryWidth();
   if (width.has_value()) {
     rtFit.width = width.value();
     GetWidthWithoutMargin(rtFit.width);
@@ -3381,7 +3387,7 @@
     rtFit.width = rtImage.width;
   }
 
-  Optional<float> height = TryHeight();
+  absl::optional<float> height = TryHeight();
   if (height.has_value()) {
     rtFit.height = height.value();
     GetHeightWithoutMargin(rtFit.height);
@@ -3447,11 +3453,11 @@
   if (margin)
     fWidthCalc += margin->GetLeftInset() + margin->GetRightInset();
 
-  Optional<float> min = TryMinWidth();
+  absl::optional<float> min = TryMinWidth();
   if (min.has_value())
     fWidthCalc = std::max(fWidthCalc, min.value());
 
-  Optional<float> max = TryMaxWidth();
+  absl::optional<float> max = TryMaxWidth();
   if (max.has_value() && max.value() > 0)
     fWidthCalc = std::min(fWidthCalc, max.value());
 
@@ -3470,11 +3476,11 @@
   if (margin)
     fHeightCalc += margin->GetTopInset() + margin->GetBottomInset();
 
-  Optional<float> min = TryMinHeight();
+  absl::optional<float> min = TryMinHeight();
   if (min.has_value())
     fHeightCalc = std::max(fHeightCalc, min.value());
 
-  Optional<float> max = TryMaxHeight();
+  absl::optional<float> max = TryMaxHeight();
   if (max.has_value() && max.value() > 0)
     fHeightCalc = std::min(fHeightCalc, max.value());
 
@@ -3504,7 +3510,7 @@
   m_pLayoutData->m_fWidgetHeight = -1;
   float fWidth = 0;
   if (*pCalcWidth > 0 && *pCalcHeight < 0) {
-    Optional<float> height = TryHeight();
+    absl::optional<float> height = TryHeight();
     if (height.has_value()) {
       *pCalcHeight = height.value();
     } else {
@@ -3517,8 +3523,8 @@
     return;
   }
   if (*pCalcWidth < 0 && *pCalcHeight < 0) {
-    Optional<float> height;
-    Optional<float> width = TryWidth();
+    absl::optional<float> height;
+    absl::optional<float> width = TryWidth();
     if (width.has_value()) {
       fWidth = width.value();
       height = TryHeight();
@@ -3578,9 +3584,9 @@
   return sz;
 }
 
-Optional<float> CXFA_Node::FindSplitPos(CXFA_FFDocView* pDocView,
-                                        size_t szBlockIndex,
-                                        float fCalcHeight) {
+absl::optional<float> CXFA_Node::FindSplitPos(CXFA_FFDocView* pDocView,
+                                              size_t szBlockIndex,
+                                              float fCalcHeight) {
   if (GetFFWidgetType() == XFA_FFWidgetType::kSubform)
     return absl::nullopt;
 
@@ -3856,7 +3862,7 @@
     pTextLayout->StartLayout(fWidth);
   }
   if (*pCalcWidth < 0 && *pCalcHeight < 0) {
-    Optional<float> width = TryWidth();
+    absl::optional<float> width = TryWidth();
     if (width.has_value()) {
       pTextLayout->StartLayout(GetWidthWithoutMargin(width.value()));
       *pCalcWidth = width.value();
@@ -3989,7 +3995,8 @@
   CXFA_Node* pText = pItems->GetFirstChild();
   int32_t i = 0;
   while (pText) {
-    Optional<WideString> wsContent = pText->JSObject()->TryContent(false, true);
+    absl::optional<WideString> wsContent =
+        pText->JSObject()->TryContent(false, true);
     if (wsContent == wsValue)
       return static_cast<XFA_CheckState>(i);
 
@@ -4208,8 +4215,8 @@
   return pItem->CountChildren(XFA_Element::Unknown, false);
 }
 
-Optional<WideString> CXFA_Node::GetChoiceListItem(int32_t nIndex,
-                                                  bool bSaveValue) {
+absl::optional<WideString> CXFA_Node::GetChoiceListItem(int32_t nIndex,
+                                                        bool bSaveValue) {
   std::vector<CXFA_Node*> pItemsArray;
   int32_t iCount = 0;
   for (CXFA_Node* pNode = GetFirstChild(); pNode;
@@ -4598,7 +4605,7 @@
   return false;
 }
 
-Optional<int32_t> CXFA_Node::GetNumberOfCells() {
+absl::optional<int32_t> CXFA_Node::GetNumberOfCells() {
   CXFA_Node* pUIChild = GetUIChildNode();
   if (!pUIChild)
     return absl::nullopt;
@@ -4724,7 +4731,7 @@
         auto* pPicture =
             pFormat->GetChild<CXFA_Picture>(0, XFA_Element::Picture, false);
         if (pPicture) {
-          Optional<WideString> picture =
+          absl::optional<WideString> picture =
               pPicture->JSObject()->TryContent(false, true);
           if (picture.has_value())
             return picture.value();
@@ -4759,7 +4766,7 @@
       if (pUI) {
         if (CXFA_Picture* pPicture =
                 pUI->GetChild<CXFA_Picture>(0, XFA_Element::Picture, false)) {
-          Optional<WideString> picture =
+          absl::optional<WideString> picture =
               pPicture->JSObject()->TryContent(false, true);
           if (picture.has_value())
             return picture.value();
diff --git a/xfa/fxfa/parser/cxfa_node.h b/xfa/fxfa/parser/cxfa_node.h
index c6cec42..f4344fd 100644
--- a/xfa/fxfa/parser/cxfa_node.h
+++ b/xfa/fxfa/parser/cxfa_node.h
@@ -222,7 +222,7 @@
   bool HasBindItem() const;
   CXFA_Node* GetContainerNode();
   GCedLocaleIface* GetLocale();
-  Optional<WideString> GetLocaleName();
+  absl::optional<WideString> GetLocaleName();
   XFA_AttributeValue GetIntact();
   WideString GetNameExpression();
 
@@ -252,11 +252,12 @@
 
   CXFA_Node* GetInstanceMgrOfSubform();
 
-  Optional<bool> GetDefaultBoolean(XFA_Attribute attr) const;
-  Optional<int32_t> GetDefaultInteger(XFA_Attribute attr) const;
-  Optional<CXFA_Measurement> GetDefaultMeasurement(XFA_Attribute attr) const;
-  Optional<WideString> GetDefaultCData(XFA_Attribute attr) const;
-  Optional<XFA_AttributeValue> GetDefaultEnum(XFA_Attribute attr) const;
+  absl::optional<bool> GetDefaultBoolean(XFA_Attribute attr) const;
+  absl::optional<int32_t> GetDefaultInteger(XFA_Attribute attr) const;
+  absl::optional<CXFA_Measurement> GetDefaultMeasurement(
+      XFA_Attribute attr) const;
+  absl::optional<WideString> GetDefaultCData(XFA_Attribute attr) const;
+  absl::optional<XFA_AttributeValue> GetDefaultEnum(XFA_Attribute attr) const;
 
   bool IsOpenAccess() const;
 
@@ -281,7 +282,7 @@
   WideString GetRawValue() const;
 
   int32_t GetRotate() const;
-  Optional<float> TryWidth();
+  absl::optional<float> TryWidth();
 
   CXFA_Node* GetExclGroupIfExists();
 
@@ -320,9 +321,9 @@
   void StartWidgetLayout(CXFA_FFDoc* doc,
                          float* pCalcWidth,
                          float* pCalcHeight);
-  Optional<float> FindSplitPos(CXFA_FFDocView* pDocView,
-                               size_t szBlockIndex,
-                               float fCalcHeight);
+  absl::optional<float> FindSplitPos(CXFA_FFDocView* pDocView,
+                                     size_t szBlockIndex,
+                                     float fCalcHeight);
 
   bool LoadCaption(CXFA_FFDoc* doc);
   CXFA_TextLayout* GetCaptionTextLayout();
@@ -364,7 +365,7 @@
 
   bool IsChoiceListAllowTextEntry();
   int32_t CountChoiceListItems(bool bSaveValue);
-  Optional<WideString> GetChoiceListItem(int32_t nIndex, bool bSaveValue);
+  absl::optional<WideString> GetChoiceListItem(int32_t nIndex, bool bSaveValue);
   bool IsChoiceListMultiSelect();
   bool IsChoiceListCommitOnSelect();
   std::vector<WideString> GetChoiceListItems(bool bSaveValue);
@@ -394,7 +395,7 @@
 
   bool IsHorizontalScrollPolicyOff();
   bool IsVerticalScrollPolicyOff();
-  Optional<int32_t> GetNumberOfCells();
+  absl::optional<int32_t> GetNumberOfCells();
 
   bool SetValue(XFA_ValuePicture eValueType, const WideString& wsValue);
   WideString GetValue(XFA_ValuePicture eValueType);
@@ -442,10 +443,11 @@
   bool HasFlag(XFA_NodeFlag dwFlag) const;
   const PropertyData* GetPropertyData(XFA_Element property) const;
   const AttributeData* GetAttributeData(XFA_Attribute attr) const;
-  Optional<XFA_Element> GetFirstPropertyWithFlag(XFA_PropertyFlag flag) const;
+  absl::optional<XFA_Element> GetFirstPropertyWithFlag(
+      XFA_PropertyFlag flag) const;
   void OnRemoved(bool bNotify) const;
-  Optional<void*> GetDefaultValue(XFA_Attribute attr,
-                                  XFA_AttributeType eType) const;
+  absl::optional<void*> GetDefaultValue(XFA_Attribute attr,
+                                        XFA_AttributeType eType) const;
   CXFA_Node* GetChildInternal(size_t index,
                               XFA_Element eType,
                               bool bOnlyChild) const;
@@ -494,16 +496,16 @@
   void SyncValue(const WideString& wsValue, bool bNotify);
   CXFA_Value* GetDefaultValueIfExists();
   CXFA_Bind* GetBindIfExists() const;
-  Optional<XFA_AttributeValue> GetIntactFromKeep(
+  absl::optional<XFA_AttributeValue> GetIntactFromKeep(
       const CXFA_Keep* pKeep,
       XFA_AttributeValue eLayoutType) const;
   CXFA_Node* GetTransparentParent();
 
-  Optional<float> TryHeight();
-  Optional<float> TryMinWidth();
-  Optional<float> TryMinHeight();
-  Optional<float> TryMaxWidth();
-  Optional<float> TryMaxHeight();
+  absl::optional<float> TryHeight();
+  absl::optional<float> TryMinWidth();
+  absl::optional<float> TryMinHeight();
+  absl::optional<float> TryMaxWidth();
+  absl::optional<float> TryMaxHeight();
   XFA_EventError ProcessEventInternal(CXFA_FFDocView* pDocView,
                                       XFA_AttributeValue iActivity,
                                       CXFA_Event* event,
diff --git a/xfa/fxfa/parser/cxfa_occur.cpp b/xfa/fxfa/parser/cxfa_occur.cpp
index 18084ae..67ef712 100644
--- a/xfa/fxfa/parser/cxfa_occur.cpp
+++ b/xfa/fxfa/parser/cxfa_occur.cpp
@@ -41,12 +41,14 @@
 CXFA_Occur::~CXFA_Occur() = default;
 
 int32_t CXFA_Occur::GetMax() {
-  Optional<int32_t> max = JSObject()->TryInteger(XFA_Attribute::Max, true);
+  absl::optional<int32_t> max =
+      JSObject()->TryInteger(XFA_Attribute::Max, true);
   return max.has_value() ? max.value() : GetMin();
 }
 
 int32_t CXFA_Occur::GetMin() {
-  Optional<int32_t> min = JSObject()->TryInteger(XFA_Attribute::Min, true);
+  absl::optional<int32_t> min =
+      JSObject()->TryInteger(XFA_Attribute::Min, true);
   return min.has_value() && min.value() >= 0 ? min.value() : 1;
 }
 
@@ -54,7 +56,7 @@
   int32_t iMin = GetMin();
   int32_t iMax = GetMax();
 
-  Optional<int32_t> init =
+  absl::optional<int32_t> init =
       JSObject()->TryInteger(XFA_Attribute::Initial, false);
   return {iMin, iMax,
           init.has_value() && init.value() >= iMin ? init.value() : iMin};
diff --git a/xfa/fxfa/parser/cxfa_script.cpp b/xfa/fxfa/parser/cxfa_script.cpp
index 1938830..e5791ca 100644
--- a/xfa/fxfa/parser/cxfa_script.cpp
+++ b/xfa/fxfa/parser/cxfa_script.cpp
@@ -48,7 +48,7 @@
 CXFA_Script::~CXFA_Script() = default;
 
 CXFA_Script::Type CXFA_Script::GetContentType() {
-  Optional<WideString> cData =
+  absl::optional<WideString> cData =
       JSObject()->TryCData(XFA_Attribute::ContentType, false);
   if (!cData.has_value())
     return Type::Formcalc;
diff --git a/xfa/fxfa/parser/cxfa_validate.cpp b/xfa/fxfa/parser/cxfa_validate.cpp
index 3cd3aba..c37c106 100644
--- a/xfa/fxfa/parser/cxfa_validate.cpp
+++ b/xfa/fxfa/parser/cxfa_validate.cpp
@@ -62,7 +62,7 @@
 }
 
 void CXFA_Validate::SetNullTest(const WideString& wsValue) {
-  Optional<XFA_AttributeValue> item =
+  absl::optional<XFA_AttributeValue> item =
       XFA_GetAttributeValueByName(wsValue.AsStringView());
   JSObject()->SetEnum(
       XFA_Attribute::NullTest,
diff --git a/xfa/fxfa/parser/xfa_basic_data.cpp b/xfa/fxfa/parser/xfa_basic_data.cpp
index 4be2101..7994f88 100644
--- a/xfa/fxfa/parser/xfa_basic_data.cpp
+++ b/xfa/fxfa/parser/xfa_basic_data.cpp
@@ -165,7 +165,7 @@
   return kPacketTable[static_cast<uint8_t>(ePacket)].info;
 }
 
-Optional<XFA_PACKETINFO> XFA_GetPacketByName(WideStringView wsName) {
+absl::optional<XFA_PACKETINFO> XFA_GetPacketByName(WideStringView wsName) {
   uint32_t hash = FX_HashCode_GetW(wsName);
   auto* elem = std::lower_bound(
       std::begin(kPacketTable), std::end(kPacketTable), hash,
@@ -196,7 +196,7 @@
   return kAttributeNames[static_cast<size_t>(attr)];
 }
 
-Optional<XFA_ATTRIBUTEINFO> XFA_GetAttributeByName(WideStringView name) {
+absl::optional<XFA_ATTRIBUTEINFO> XFA_GetAttributeByName(WideStringView name) {
   uint32_t hash = FX_HashCode_GetW(name);
   auto* elem = std::lower_bound(
       std::begin(kAttributeRecords), std::end(kAttributeRecords), hash,
@@ -218,7 +218,8 @@
   return kAttributeValueNames[static_cast<int32_t>(item)];
 }
 
-Optional<XFA_AttributeValue> XFA_GetAttributeValueByName(WideStringView name) {
+absl::optional<XFA_AttributeValue> XFA_GetAttributeValueByName(
+    WideStringView name) {
   auto* it =
       std::lower_bound(std::begin(kAttributeValueRecords),
                        std::end(kAttributeValueRecords), FX_HashCode_GetW(name),
@@ -235,10 +236,11 @@
   return it->eName;
 }
 
-Optional<XFA_SCRIPTATTRIBUTEINFO> XFA_GetScriptAttributeByName(
+absl::optional<XFA_SCRIPTATTRIBUTEINFO> XFA_GetScriptAttributeByName(
     XFA_Element element,
     WideStringView attribute_name) {
-  Optional<XFA_ATTRIBUTEINFO> attr = XFA_GetAttributeByName(attribute_name);
+  absl::optional<XFA_ATTRIBUTEINFO> attr =
+      XFA_GetAttributeByName(attribute_name);
   if (!attr.has_value())
     return absl::nullopt;
 
diff --git a/xfa/fxfa/parser/xfa_basic_data.h b/xfa/fxfa/parser/xfa_basic_data.h
index 9605b82..42ce8c6 100644
--- a/xfa/fxfa/parser/xfa_basic_data.h
+++ b/xfa/fxfa/parser/xfa_basic_data.h
@@ -51,18 +51,19 @@
 };
 
 XFA_PACKETINFO XFA_GetPacketByIndex(XFA_PacketType ePacket);
-Optional<XFA_PACKETINFO> XFA_GetPacketByName(WideStringView wsName);
+absl::optional<XFA_PACKETINFO> XFA_GetPacketByName(WideStringView wsName);
 
 ByteStringView XFA_ElementToName(XFA_Element elem);
 XFA_Element XFA_GetElementByName(WideStringView name);
 
 ByteStringView XFA_AttributeToName(XFA_Attribute attr);
-Optional<XFA_ATTRIBUTEINFO> XFA_GetAttributeByName(WideStringView name);
+absl::optional<XFA_ATTRIBUTEINFO> XFA_GetAttributeByName(WideStringView name);
 
 ByteStringView XFA_AttributeValueToName(XFA_AttributeValue item);
-Optional<XFA_AttributeValue> XFA_GetAttributeValueByName(WideStringView name);
+absl::optional<XFA_AttributeValue> XFA_GetAttributeValueByName(
+    WideStringView name);
 
-Optional<XFA_SCRIPTATTRIBUTEINFO> XFA_GetScriptAttributeByName(
+absl::optional<XFA_SCRIPTATTRIBUTEINFO> XFA_GetScriptAttributeByName(
     XFA_Element eElement,
     WideStringView wsAttributeName);
 
diff --git a/xfa/fxfa/parser/xfa_basic_data_unittest.cpp b/xfa/fxfa/parser/xfa_basic_data_unittest.cpp
index 9202703..53a80eb 100644
--- a/xfa/fxfa/parser/xfa_basic_data_unittest.cpp
+++ b/xfa/fxfa/parser/xfa_basic_data_unittest.cpp
@@ -7,7 +7,7 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(XFABasicDataTest, GetPacketByName) {
-  Optional<XFA_PACKETINFO> result = XFA_GetPacketByName(L"");
+  absl::optional<XFA_PACKETINFO> result = XFA_GetPacketByName(L"");
   EXPECT_FALSE(result.has_value());
 
   result = XFA_GetPacketByName(L"nonesuch");
@@ -49,7 +49,7 @@
 }
 
 TEST(XFABasicDataTest, GetAttributeByName) {
-  Optional<XFA_ATTRIBUTEINFO> result = XFA_GetAttributeByName(L"");
+  absl::optional<XFA_ATTRIBUTEINFO> result = XFA_GetAttributeByName(L"");
   EXPECT_FALSE(result.has_value());
 
   result = XFA_GetAttributeByName(L"nonesuch");
@@ -74,7 +74,7 @@
 }
 
 TEST(XFABasicDataTest, GetAttributeValueByName) {
-  Optional<XFA_AttributeValue> result = XFA_GetAttributeValueByName(L"");
+  absl::optional<XFA_AttributeValue> result = XFA_GetAttributeValueByName(L"");
   EXPECT_FALSE(result.has_value());
 
   result = XFA_GetAttributeValueByName(L"nonesuch");
diff --git a/xfa/fxfa/parser/xfa_utils.cpp b/xfa/fxfa/parser/xfa_utils.cpp
index 6541e63..2f199cf 100644
--- a/xfa/fxfa/parser/xfa_utils.cpp
+++ b/xfa/fxfa/parser/xfa_utils.cpp
@@ -112,7 +112,7 @@
 }
 
 bool ContentNodeNeedtoExport(CXFA_Node* pContentNode) {
-  Optional<WideString> wsContent =
+  absl::optional<WideString> wsContent =
       pContentNode->JSObject()->TryContent(false, false);
   if (!wsContent.has_value())
     return false;
@@ -140,7 +140,8 @@
   if (!bProto && !pNode->JSObject()->HasAttribute(eName))
     return;
 
-  Optional<WideString> value = pNode->JSObject()->TryAttribute(eName, false);
+  absl::optional<WideString> value =
+      pNode->JSObject()->TryAttribute(eName, false);
   if (!value.has_value())
     return;
 
@@ -186,7 +187,7 @@
       if (!pRawValueNode)
         break;
 
-      Optional<WideString> contentType =
+      absl::optional<WideString> contentType =
           pNode->JSObject()->TryAttribute(XFA_Attribute::ContentType, false);
       if (pRawValueNode->GetElementType() == XFA_Element::SharpxHTML &&
           contentType.has_value() &&
@@ -206,8 +207,9 @@
       } else if (pRawValueNode->GetElementType() == XFA_Element::Sharpxml &&
                  contentType.has_value() &&
                  contentType.value().EqualsASCII("text/xml")) {
-        Optional<WideString> rawValue = pRawValueNode->JSObject()->TryAttribute(
-            XFA_Attribute::Value, false);
+        absl::optional<WideString> rawValue =
+            pRawValueNode->JSObject()->TryAttribute(XFA_Attribute::Value,
+                                                    false);
         if (!rawValue.has_value() || rawValue->IsEmpty())
           break;
 
@@ -348,7 +350,8 @@
   if (!pTemplateRoot)
     return WideString();
 
-  Optional<WideString> templateNS = pTemplateRoot->JSObject()->TryNamespace();
+  absl::optional<WideString> templateNS =
+      pTemplateRoot->JSObject()->TryNamespace();
   if (!templateNS.has_value())
     return WideString();