Convert string class names

Automated using git grep & sed.
Replace StringC classes with StringView classes.
Remove the CFX_ prefix and put string classes in fxcrt namespace.
Change AsStringC() to AsStringView().
Rename tests from TEST(fxcrt, *String*Foo) to TEST(*String*,
Foo).
Couple of tests needed to have their names regularlized.

BUG=pdfium:894

Change-Id: I7ca038685c8d803795f3ed02545124f7a224c83d
Reviewed-on: https://pdfium-review.googlesource.com/14151
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

45 files changed, 305 insertions, 320 deletions

diff --git a/core/fpdfapi/parser/cfdf_document.cpp b/core/fpdfapi/parser/cfdf_document.cpp
index 41827db0d9..1f84f56547 100644
--- a/core/fpdfapi/parser/cfdf_document.cpp
+++ b/core/fpdfapi/parser/cfdf_document.cpp
@@ -52,7 +52,7 @@ void CFDF_Document::ParseStream(
   parser.InitParser(m_pFile, 0);
   while (1) {
     bool bNumber;
-    CFX_ByteString word = parser.GetNextWord(&bNumber);
+    ByteString word = parser.GetNextWord(&bNumber);
     if (bNumber) {
       uint32_t objnum = FXSYS_atoui(word.c_str());
       if (!objnum)
@@ -89,9 +89,9 @@ void CFDF_Document::ParseStream(
   }
 }
 
-CFX_ByteString CFDF_Document::WriteToString() const {
+ByteString CFDF_Document::WriteToString() const {
   if (!m_pRootDict)
-    return CFX_ByteString();
+    return ByteString();
 
   std::ostringstream buf;
   buf << "%FDF-1.2\r\n";
@@ -102,5 +102,5 @@ CFX_ByteString CFDF_Document::WriteToString() const {
   buf << "trailer\r\n<</Root " << m_pRootDict->GetObjNum()
       << " 0 R>>\r\n%%EOF\r\n";
 
-  return CFX_ByteString(buf);
+  return ByteString(buf);
 }
diff --git a/core/fpdfapi/parser/cfdf_document.h b/core/fpdfapi/parser/cfdf_document.h
index d58f93ced4..a24415b099 100644
--- a/core/fpdfapi/parser/cfdf_document.h
+++ b/core/fpdfapi/parser/cfdf_document.h
@@ -27,7 +27,7 @@ class CFDF_Document : public CPDF_IndirectObjectHolder {
   CFDF_Document();
   ~CFDF_Document() override;
 
-  CFX_ByteString WriteToString() const;
+  ByteString WriteToString() const;
   CPDF_Dictionary* GetRoot() const { return m_pRootDict.Get(); }
 
  protected:
diff --git a/core/fpdfapi/parser/cpdf_array.cpp b/core/fpdfapi/parser/cpdf_array.cpp
index a0957b6c2b..f4907ffdf1 100644
--- a/core/fpdfapi/parser/cpdf_array.cpp
+++ b/core/fpdfapi/parser/cpdf_array.cpp
@@ -20,7 +20,7 @@
 
 CPDF_Array::CPDF_Array() {}
 
-CPDF_Array::CPDF_Array(const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
+CPDF_Array::CPDF_Array(const CFX_WeakPtr<ByteStringPool>& pPool)
     : m_pPool(pPool) {}
 
 CPDF_Array::~CPDF_Array() {
@@ -100,15 +100,15 @@ CPDF_Object* CPDF_Array::GetDirectObjectAt(size_t i) const {
   return m_Objects[i]->GetDirect();
 }
 
-CFX_ByteString CPDF_Array::GetStringAt(size_t i) const {
+ByteString CPDF_Array::GetStringAt(size_t i) const {
   if (i >= m_Objects.size())
-    return CFX_ByteString();
+    return ByteString();
   return m_Objects[i]->GetString();
 }
 
-CFX_WideString CPDF_Array::GetUnicodeTextAt(size_t i) const {
+WideString CPDF_Array::GetUnicodeTextAt(size_t i) const {
   if (i >= m_Objects.size())
-    return CFX_WideString();
+    return WideString();
   return m_Objects[i]->GetUnicodeText();
 }
 
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
index d1be233652..3b18025b2d 100644
--- a/core/fpdfapi/parser/cpdf_array.h
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -24,7 +24,7 @@ class CPDF_Array : public CPDF_Object {
       std::vector<std::unique_ptr<CPDF_Object>>::const_iterator;
 
   CPDF_Array();
-  explicit CPDF_Array(const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
+  explicit CPDF_Array(const CFX_WeakPtr<ByteStringPool>& pPool);
   ~CPDF_Array() override;
 
   // CPDF_Object:
@@ -39,8 +39,8 @@ class CPDF_Array : public CPDF_Object {
   size_t GetCount() const { return m_Objects.size(); }
   CPDF_Object* GetObjectAt(size_t index) const;
   CPDF_Object* GetDirectObjectAt(size_t index) const;
-  CFX_ByteString GetStringAt(size_t index) const;
-  CFX_WideString GetUnicodeTextAt(size_t index) const;
+  ByteString GetStringAt(size_t index) const;
+  WideString GetUnicodeTextAt(size_t index) const;
   int GetIntegerAt(size_t index) const;
   float GetNumberAt(size_t index) const;
   CPDF_Dictionary* GetDictAt(size_t index) const;
@@ -112,7 +112,7 @@ class CPDF_Array : public CPDF_Object {
       std::set<const CPDF_Object*>* pVisited) const override;
 
   std::vector<std::unique_ptr<CPDF_Object>> m_Objects;
-  CFX_WeakPtr<CFX_ByteStringPool> m_pPool;
+  CFX_WeakPtr<ByteStringPool> m_pPool;
 };
 
 inline CPDF_Array* ToArray(CPDF_Object* obj) {
diff --git a/core/fpdfapi/parser/cpdf_boolean.cpp b/core/fpdfapi/parser/cpdf_boolean.cpp
index 2633c876d3..a1dc450519 100644
--- a/core/fpdfapi/parser/cpdf_boolean.cpp
+++ b/core/fpdfapi/parser/cpdf_boolean.cpp
@@ -22,7 +22,7 @@ std::unique_ptr<CPDF_Object> CPDF_Boolean::Clone() const {
   return pdfium::MakeUnique<CPDF_Boolean>(m_bValue);
 }
 
-CFX_ByteString CPDF_Boolean::GetString() const {
+ByteString CPDF_Boolean::GetString() const {
   return m_bValue ? "true" : "false";
 }
 
@@ -30,7 +30,7 @@ int CPDF_Boolean::GetInteger() const {
   return m_bValue;
 }
 
-void CPDF_Boolean::SetString(const CFX_ByteString& str) {
+void CPDF_Boolean::SetString(const ByteString& str) {
   m_bValue = (str == "true");
 }
 
@@ -48,5 +48,5 @@ const CPDF_Boolean* CPDF_Boolean::AsBoolean() const {
 
 bool CPDF_Boolean::WriteTo(IFX_ArchiveStream* archive) const {
   return archive->WriteString(" ") &&
-         archive->WriteString(GetString().AsStringC());
+         archive->WriteString(GetString().AsStringView());
 }
diff --git a/core/fpdfapi/parser/cpdf_boolean.h b/core/fpdfapi/parser/cpdf_boolean.h
index 2dd1486b6a..c0a69d8932 100644
--- a/core/fpdfapi/parser/cpdf_boolean.h
+++ b/core/fpdfapi/parser/cpdf_boolean.h
@@ -22,9 +22,9 @@ class CPDF_Boolean : public CPDF_Object {
   // CPDF_Object:
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
-  CFX_ByteString GetString() const override;
+  ByteString GetString() const override;
   int GetInteger() const override;
-  void SetString(const CFX_ByteString& str) override;
+  void SetString(const ByteString& str) override;
   bool IsBoolean() const override;
   CPDF_Boolean* AsBoolean() override;
   const CPDF_Boolean* AsBoolean() const override;
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.cpp b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
index 74428ba6a8..cae95f2c19 100644
--- a/core/fpdfapi/parser/cpdf_crypto_handler.cpp
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
@@ -230,14 +230,14 @@ bool CPDF_CryptoHandler::CryptFinish(void* context,
   return true;
 }
 
-CFX_ByteString CPDF_CryptoHandler::Decrypt(uint32_t objnum,
-                                           uint32_t gennum,
-                                           const CFX_ByteString& str) {
+ByteString CPDF_CryptoHandler::Decrypt(uint32_t objnum,
+                                       uint32_t gennum,
+                                       const ByteString& str) {
   CFX_BinaryBuf dest_buf;
   void* context = DecryptStart(objnum, gennum);
   DecryptStream(context, str.raw_str(), str.GetLength(), dest_buf);
   DecryptFinish(context, dest_buf);
-  return CFX_ByteString(dest_buf.GetBuffer(), dest_buf.GetSize());
+  return ByteString(dest_buf.GetBuffer(), dest_buf.GetSize());
 }
 
 void* CPDF_CryptoHandler::DecryptStart(uint32_t objnum, uint32_t gennum) {
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.h b/core/fpdfapi/parser/cpdf_crypto_handler.h
index adf0c6c680..252f41c333 100644
--- a/core/fpdfapi/parser/cpdf_crypto_handler.h
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.h
@@ -28,9 +28,7 @@ class CPDF_CryptoHandler : public CFX_Retainable {
             CPDF_SecurityHandler* pSecurityHandler);
   uint32_t DecryptGetSize(uint32_t src_size);
   void* DecryptStart(uint32_t objnum, uint32_t gennum);
-  CFX_ByteString Decrypt(uint32_t objnum,
-                         uint32_t gennum,
-                         const CFX_ByteString& str);
+  ByteString Decrypt(uint32_t objnum, uint32_t gennum, const ByteString& str);
   bool DecryptStream(void* context,
                      const uint8_t* src_buf,
                      uint32_t src_size,
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index b10029d4ce..994d082712 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -473,7 +473,7 @@ bool CPDF_DataAvail::CheckPage() {
     if (!pObj->IsDictionary())
       continue;
 
-    CFX_ByteString type = pObj->GetDict()->GetStringFor("Type");
+    ByteString type = pObj->GetDict()->GetStringFor("Type");
     if (type == "Pages") {
       m_PagesArray.push_back(std::move(pObj));
       continue;
@@ -661,7 +661,7 @@ std::unique_ptr<CPDF_Object> CPDF_DataAvail::ParseIndirectObjectAt(
   m_syntaxParser.SetPos(pos);
 
   bool bIsNumber;
-  CFX_ByteString word = m_syntaxParser.GetNextWord(&bIsNumber);
+  ByteString word = m_syntaxParser.GetNextWord(&bIsNumber);
   if (!bIsNumber)
     return nullptr;
 
@@ -723,7 +723,7 @@ bool CPDF_DataAvail::IsLinearizedFile(uint8_t* pData, uint32_t dwLen) {
   m_syntaxParser.SetPos(m_syntaxParser.m_HeaderOffset + 9);
 
   bool bNumber;
-  CFX_ByteString wordObjNum = m_syntaxParser.GetNextWord(&bNumber);
+  ByteString wordObjNum = m_syntaxParser.GetNextWord(&bNumber);
   if (!bNumber)
     return false;
 
@@ -761,7 +761,7 @@ bool CPDF_DataAvail::CheckEnd() {
   m_syntaxParser.GetNextWord(nullptr);
 
   bool bNumber;
-  CFX_ByteString xrefpos_str = m_syntaxParser.GetNextWord(&bNumber);
+  ByteString xrefpos_str = m_syntaxParser.GetNextWord(&bNumber);
   if (!bNumber) {
     m_docStatus = PDF_DATAAVAIL_ERROR;
     return false;
@@ -781,7 +781,7 @@ void CPDF_DataAvail::SetStartOffset(FX_FILESIZE dwOffset) {
   m_Pos = dwOffset;
 }
 
-bool CPDF_DataAvail::GetNextToken(CFX_ByteString* token) {
+bool CPDF_DataAvail::GetNextToken(ByteString* token) {
   uint8_t ch;
   if (!GetNextChar(ch))
     return false;
@@ -814,7 +814,7 @@ bool CPDF_DataAvail::GetNextToken(CFX_ByteString* token) {
 
         if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) {
           m_Pos--;
-          *token = CFX_ByteString(buffer, index);
+          *token = ByteString(buffer, index);
           return true;
         }
         if (index < sizeof(buffer))
@@ -837,7 +837,7 @@ bool CPDF_DataAvail::GetNextToken(CFX_ByteString* token) {
       else
         m_Pos--;
     }
-    *token = CFX_ByteString(buffer, index);
+    *token = ByteString(buffer, index);
     return true;
   }
 
@@ -854,7 +854,7 @@ bool CPDF_DataAvail::GetNextToken(CFX_ByteString* token) {
     }
   }
 
-  *token = CFX_ByteString(buffer, index);
+  *token = ByteString(buffer, index);
   return true;
 }
 
@@ -885,7 +885,7 @@ bool CPDF_DataAvail::GetNextChar(uint8_t& ch) {
 }
 
 bool CPDF_DataAvail::CheckCrossRefItem() {
-  CFX_ByteString token;
+  ByteString token;
   while (1) {
     const CPDF_ReadValidator::Session read_session(GetValidator().Get());
     if (!GetNextToken(&token)) {
@@ -904,7 +904,7 @@ bool CPDF_DataAvail::CheckCrossRefItem() {
 
 bool CPDF_DataAvail::CheckCrossRef() {
   const CPDF_ReadValidator::Session read_session(GetValidator().Get());
-  CFX_ByteString token;
+  ByteString token;
   if (!GetNextToken(&token)) {
     if (!GetValidator()->has_read_problems())
       m_docStatus = PDF_DATAAVAIL_ERROR;
@@ -1046,7 +1046,7 @@ bool CPDF_DataAvail::CheckUnknownPageNode(uint32_t dwPageNo,
 
   pPageNode->m_dwPageNo = dwPageNo;
   CPDF_Dictionary* pDict = pPage->GetDict();
-  const CFX_ByteString type = pDict->GetStringFor("Type");
+  const ByteString type = pDict->GetStringFor("Type");
   if (type == "Page") {
     pPageNode->m_type = PDF_PAGENODE_PAGE;
     return true;
diff --git a/core/fpdfapi/parser/cpdf_data_avail.h b/core/fpdfapi/parser/cpdf_data_avail.h
index e2a4a20aa1..850ceeaae2 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.h
+++ b/core/fpdfapi/parser/cpdf_data_avail.h
@@ -145,7 +145,7 @@ class CPDF_DataAvail final {
 
   bool IsLinearizedFile(uint8_t* pData, uint32_t dwLen);
   void SetStartOffset(FX_FILESIZE dwOffset);
-  bool GetNextToken(CFX_ByteString* token);
+  bool GetNextToken(ByteString* token);
   bool GetNextChar(uint8_t& ch);
   std::unique_ptr<CPDF_Object> ParseIndirectObjectAt(
       FX_FILESIZE pos,
@@ -200,7 +200,7 @@ class CPDF_DataAvail final {
   FX_FILESIZE m_Pos;
   FX_FILESIZE m_bufferOffset;
   uint32_t m_bufferSize;
-  CFX_ByteString m_WordBuf;
+  ByteString m_WordBuf;
   uint8_t m_bufferData[512];
   std::vector<uint32_t> m_XRefStreamList;
   std::vector<uint32_t> m_PageObjList;
diff --git a/core/fpdfapi/parser/cpdf_dictionary.cpp b/core/fpdfapi/parser/cpdf_dictionary.cpp
index 4c035871df..570c57e557 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.cpp
+++ b/core/fpdfapi/parser/cpdf_dictionary.cpp
@@ -22,9 +22,9 @@
 #include "third_party/base/stl_util.h"
 
 CPDF_Dictionary::CPDF_Dictionary()
-    : CPDF_Dictionary(CFX_WeakPtr<CFX_ByteStringPool>()) {}
+    : CPDF_Dictionary(CFX_WeakPtr<ByteStringPool>()) {}
 
-CPDF_Dictionary::CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
+CPDF_Dictionary::CPDF_Dictionary(const CFX_WeakPtr<ByteStringPool>& pPool)
     : m_pPool(pPool) {}
 
 CPDF_Dictionary::~CPDF_Dictionary() {
@@ -78,58 +78,56 @@ std::unique_ptr<CPDF_Object> CPDF_Dictionary::CloneNonCyclic(
   return std::move(pCopy);
 }
 
-CPDF_Object* CPDF_Dictionary::GetObjectFor(const CFX_ByteString& key) const {
+CPDF_Object* CPDF_Dictionary::GetObjectFor(const ByteString& key) const {
   auto it = m_Map.find(key);
   return it != m_Map.end() ? it->second.get() : nullptr;
 }
 
-CPDF_Object* CPDF_Dictionary::GetDirectObjectFor(
-    const CFX_ByteString& key) const {
+CPDF_Object* CPDF_Dictionary::GetDirectObjectFor(const ByteString& key) const {
   CPDF_Object* p = GetObjectFor(key);
   return p ? p->GetDirect() : nullptr;
 }
 
-CFX_ByteString CPDF_Dictionary::GetStringFor(const CFX_ByteString& key) const {
+ByteString CPDF_Dictionary::GetStringFor(const ByteString& key) const {
   CPDF_Object* p = GetObjectFor(key);
-  return p ? p->GetString() : CFX_ByteString();
+  return p ? p->GetString() : ByteString();
 }
 
-CFX_WideString CPDF_Dictionary::GetUnicodeTextFor(
-    const CFX_ByteString& key) const {
+WideString CPDF_Dictionary::GetUnicodeTextFor(const ByteString& key) const {
   CPDF_Object* p = GetObjectFor(key);
   if (CPDF_Reference* pRef = ToReference(p))
     p = pRef->GetDirect();
-  return p ? p->GetUnicodeText() : CFX_WideString();
+  return p ? p->GetUnicodeText() : WideString();
 }
 
-CFX_ByteString CPDF_Dictionary::GetStringFor(const CFX_ByteString& key,
-                                             const CFX_ByteString& def) const {
+ByteString CPDF_Dictionary::GetStringFor(const ByteString& key,
+                                         const ByteString& def) const {
   CPDF_Object* p = GetObjectFor(key);
-  return p ? p->GetString() : CFX_ByteString(def);
+  return p ? p->GetString() : ByteString(def);
 }
 
-int CPDF_Dictionary::GetIntegerFor(const CFX_ByteString& key) const {
+int CPDF_Dictionary::GetIntegerFor(const ByteString& key) const {
   CPDF_Object* p = GetObjectFor(key);
   return p ? p->GetInteger() : 0;
 }
 
-int CPDF_Dictionary::GetIntegerFor(const CFX_ByteString& key, int def) const {
+int CPDF_Dictionary::GetIntegerFor(const ByteString& key, int def) const {
   CPDF_Object* p = GetObjectFor(key);
   return p ? p->GetInteger() : def;
 }
 
-float CPDF_Dictionary::GetNumberFor(const CFX_ByteString& key) const {
+float CPDF_Dictionary::GetNumberFor(const ByteString& key) const {
   CPDF_Object* p = GetObjectFor(key);
   return p ? p->GetNumber() : 0;
 }
 
-bool CPDF_Dictionary::GetBooleanFor(const CFX_ByteString& key,
+bool CPDF_Dictionary::GetBooleanFor(const ByteString& key,
                                     bool bDefault) const {
   CPDF_Object* p = GetObjectFor(key);
   return ToBoolean(p) ? p->GetInteger() != 0 : bDefault;
 }
 
-CPDF_Dictionary* CPDF_Dictionary::GetDictFor(const CFX_ByteString& key) const {
+CPDF_Dictionary* CPDF_Dictionary::GetDictFor(const ByteString& key) const {
   CPDF_Object* p = GetDirectObjectFor(key);
   if (!p)
     return nullptr;
@@ -140,15 +138,15 @@ CPDF_Dictionary* CPDF_Dictionary::GetDictFor(const CFX_ByteString& key) const {
   return nullptr;
 }
 
-CPDF_Array* CPDF_Dictionary::GetArrayFor(const CFX_ByteString& key) const {
+CPDF_Array* CPDF_Dictionary::GetArrayFor(const ByteString& key) const {
   return ToArray(GetDirectObjectFor(key));
 }
 
-CPDF_Stream* CPDF_Dictionary::GetStreamFor(const CFX_ByteString& key) const {
+CPDF_Stream* CPDF_Dictionary::GetStreamFor(const ByteString& key) const {
   return ToStream(GetDirectObjectFor(key));
 }
 
-CFX_FloatRect CPDF_Dictionary::GetRectFor(const CFX_ByteString& key) const {
+CFX_FloatRect CPDF_Dictionary::GetRectFor(const ByteString& key) const {
   CFX_FloatRect rect;
   CPDF_Array* pArray = GetArrayFor(key);
   if (pArray)
@@ -156,7 +154,7 @@ CFX_FloatRect CPDF_Dictionary::GetRectFor(const CFX_ByteString& key) const {
   return rect;
 }
 
-CFX_Matrix CPDF_Dictionary::GetMatrixFor(const CFX_ByteString& key) const {
+CFX_Matrix CPDF_Dictionary::GetMatrixFor(const ByteString& key) const {
   CFX_Matrix matrix;
   CPDF_Array* pArray = GetArrayFor(key);
   if (pArray)
@@ -164,7 +162,7 @@ CFX_Matrix CPDF_Dictionary::GetMatrixFor(const CFX_ByteString& key) const {
   return matrix;
 }
 
-bool CPDF_Dictionary::KeyExist(const CFX_ByteString& key) const {
+bool CPDF_Dictionary::KeyExist(const ByteString& key) const {
   return pdfium::ContainsKey(m_Map, key);
 }
 
@@ -175,7 +173,7 @@ bool CPDF_Dictionary::IsSignatureDict() const {
   return pType && pType->GetString() == "Sig";
 }
 
-CPDF_Object* CPDF_Dictionary::SetFor(const CFX_ByteString& key,
+CPDF_Object* CPDF_Dictionary::SetFor(const ByteString& key,
                                      std::unique_ptr<CPDF_Object> pObj) {
   if (!pObj) {
     m_Map.erase(key);
@@ -188,7 +186,7 @@ CPDF_Object* CPDF_Dictionary::SetFor(const CFX_ByteString& key,
 }
 
 void CPDF_Dictionary::ConvertToIndirectObjectFor(
-    const CFX_ByteString& key,
+    const ByteString& key,
     CPDF_IndirectObjectHolder* pHolder) {
   auto it = m_Map.find(key);
   if (it == m_Map.end() || it->second->IsReference())
@@ -198,8 +196,7 @@ void CPDF_Dictionary::ConvertToIndirectObjectFor(
   it->second = pdfium::MakeUnique<CPDF_Reference>(pHolder, pObj->GetObjNum());
 }
 
-std::unique_ptr<CPDF_Object> CPDF_Dictionary::RemoveFor(
-    const CFX_ByteString& key) {
+std::unique_ptr<CPDF_Object> CPDF_Dictionary::RemoveFor(const ByteString& key) {
   std::unique_ptr<CPDF_Object> result;
   auto it = m_Map.find(key);
   if (it != m_Map.end()) {
@@ -209,8 +206,8 @@ std::unique_ptr<CPDF_Object> CPDF_Dictionary::RemoveFor(
   return result;
 }
 
-void CPDF_Dictionary::ReplaceKey(const CFX_ByteString& oldkey,
-                                 const CFX_ByteString& newkey) {
+void CPDF_Dictionary::ReplaceKey(const ByteString& oldkey,
+                                 const ByteString& newkey) {
   auto old_it = m_Map.find(oldkey);
   if (old_it == m_Map.end())
     return;
@@ -223,7 +220,7 @@ void CPDF_Dictionary::ReplaceKey(const CFX_ByteString& oldkey,
   m_Map.erase(old_it);
 }
 
-void CPDF_Dictionary::SetRectFor(const CFX_ByteString& key,
+void CPDF_Dictionary::SetRectFor(const ByteString& key,
                                  const CFX_FloatRect& rect) {
   CPDF_Array* pArray = SetNewFor<CPDF_Array>(key);
   pArray->AddNew<CPDF_Number>(rect.left);
@@ -232,7 +229,7 @@ void CPDF_Dictionary::SetRectFor(const CFX_ByteString& key,
   pArray->AddNew<CPDF_Number>(rect.top);
 }
 
-void CPDF_Dictionary::SetMatrixFor(const CFX_ByteString& key,
+void CPDF_Dictionary::SetMatrixFor(const ByteString& key,
                                    const CFX_Matrix& matrix) {
   CPDF_Array* pArray = SetNewFor<CPDF_Array>(key);
   pArray->AddNew<CPDF_Number>(matrix.a);
@@ -243,7 +240,7 @@ void CPDF_Dictionary::SetMatrixFor(const CFX_ByteString& key,
   pArray->AddNew<CPDF_Number>(matrix.f);
 }
 
-CFX_ByteString CPDF_Dictionary::MaybeIntern(const CFX_ByteString& str) {
+ByteString CPDF_Dictionary::MaybeIntern(const ByteString& str) {
   return m_pPool ? m_pPool->Intern(str) : str;
 }
 
@@ -252,10 +249,10 @@ bool CPDF_Dictionary::WriteTo(IFX_ArchiveStream* archive) const {
     return false;
 
   for (const auto& it : *this) {
-    const CFX_ByteString& key = it.first;
+    const ByteString& key = it.first;
     CPDF_Object* pValue = it.second.get();
     if (!archive->WriteString("/") ||
-        !archive->WriteString(PDF_NameEncode(key).AsStringC())) {
+        !archive->WriteString(PDF_NameEncode(key).AsStringView())) {
       return false;
     }
 
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
index 31a09d954d..93c00c8c10 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.h
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -24,10 +24,10 @@ class CPDF_IndirectObjectHolder;
 class CPDF_Dictionary : public CPDF_Object {
  public:
   using const_iterator =
-      std::map<CFX_ByteString, std::unique_ptr<CPDF_Object>>::const_iterator;
+      std::map<ByteString, std::unique_ptr<CPDF_Object>>::const_iterator;
 
   CPDF_Dictionary();
-  explicit CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
+  explicit CPDF_Dictionary(const CFX_WeakPtr<ByteStringPool>& pPool);
   ~CPDF_Dictionary() override;
 
   // CPDF_Object:
@@ -40,76 +40,73 @@ class CPDF_Dictionary : public CPDF_Object {
   bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   size_t GetCount() const { return m_Map.size(); }
-  CPDF_Object* GetObjectFor(const CFX_ByteString& key) const;
-  CPDF_Object* GetDirectObjectFor(const CFX_ByteString& key) const;
-  CFX_ByteString GetStringFor(const CFX_ByteString& key) const;
-  CFX_ByteString GetStringFor(const CFX_ByteString& key,
-                              const CFX_ByteString& default_str) const;
-  CFX_WideString GetUnicodeTextFor(const CFX_ByteString& key) const;
-  int GetIntegerFor(const CFX_ByteString& key) const;
-  int GetIntegerFor(const CFX_ByteString& key, int default_int) const;
-  bool GetBooleanFor(const CFX_ByteString& key, bool bDefault = false) const;
-  float GetNumberFor(const CFX_ByteString& key) const;
-  CPDF_Dictionary* GetDictFor(const CFX_ByteString& key) const;
-  CPDF_Stream* GetStreamFor(const CFX_ByteString& key) const;
-  CPDF_Array* GetArrayFor(const CFX_ByteString& key) const;
-  CFX_FloatRect GetRectFor(const CFX_ByteString& key) const;
-  CFX_Matrix GetMatrixFor(const CFX_ByteString& key) const;
-  float GetFloatFor(const CFX_ByteString& key) const {
-    return GetNumberFor(key);
-  }
-
-  bool KeyExist(const CFX_ByteString& key) const;
+  CPDF_Object* GetObjectFor(const ByteString& key) const;
+  CPDF_Object* GetDirectObjectFor(const ByteString& key) const;
+  ByteString GetStringFor(const ByteString& key) const;
+  ByteString GetStringFor(const ByteString& key,
+                          const ByteString& default_str) const;
+  WideString GetUnicodeTextFor(const ByteString& key) const;
+  int GetIntegerFor(const ByteString& key) const;
+  int GetIntegerFor(const ByteString& key, int default_int) const;
+  bool GetBooleanFor(const ByteString& key, bool bDefault = false) const;
+  float GetNumberFor(const ByteString& key) const;
+  CPDF_Dictionary* GetDictFor(const ByteString& key) const;
+  CPDF_Stream* GetStreamFor(const ByteString& key) const;
+  CPDF_Array* GetArrayFor(const ByteString& key) const;
+  CFX_FloatRect GetRectFor(const ByteString& key) const;
+  CFX_Matrix GetMatrixFor(const ByteString& key) const;
+  float GetFloatFor(const ByteString& key) const { return GetNumberFor(key); }
+
+  bool KeyExist(const ByteString& key) const;
   bool IsSignatureDict() const;
 
   // Set* functions invalidate iterators for the element with the key |key|.
   // Takes ownership of |pObj|, returns an unowned pointer to it.
-  CPDF_Object* SetFor(const CFX_ByteString& key,
-                      std::unique_ptr<CPDF_Object> pObj);
+  CPDF_Object* SetFor(const ByteString& key, std::unique_ptr<CPDF_Object> pObj);
 
   // Creates a new object owned by the dictionary and returns an unowned
   // pointer to it.
   template <typename T, typename... Args>
   typename std::enable_if<!CanInternStrings<T>::value, T*>::type SetNewFor(
-      const CFX_ByteString& key,
+      const ByteString& key,
       Args&&... args) {
     return static_cast<T*>(
         SetFor(key, pdfium::MakeUnique<T>(std::forward<Args>(args)...)));
   }
   template <typename T, typename... Args>
   typename std::enable_if<CanInternStrings<T>::value, T*>::type SetNewFor(
-      const CFX_ByteString& key,
+      const ByteString& key,
       Args&&... args) {
     return static_cast<T*>(SetFor(
         key, pdfium::MakeUnique<T>(m_pPool, std::forward<Args>(args)...)));
   }
 
   // Convenience functions to convert native objects to array form.
-  void SetRectFor(const CFX_ByteString& key, const CFX_FloatRect& rect);
-  void SetMatrixFor(const CFX_ByteString& key, const CFX_Matrix& matrix);
+  void SetRectFor(const ByteString& key, const CFX_FloatRect& rect);
+  void SetMatrixFor(const ByteString& key, const CFX_Matrix& matrix);
 
-  void ConvertToIndirectObjectFor(const CFX_ByteString& key,
+  void ConvertToIndirectObjectFor(const ByteString& key,
                                   CPDF_IndirectObjectHolder* pHolder);
 
   // Invalidates iterators for the element with the key |key|.
-  std::unique_ptr<CPDF_Object> RemoveFor(const CFX_ByteString& key);
+  std::unique_ptr<CPDF_Object> RemoveFor(const ByteString& key);
 
   // Invalidates iterators for the element with the key |oldkey|.
-  void ReplaceKey(const CFX_ByteString& oldkey, const CFX_ByteString& newkey);
+  void ReplaceKey(const ByteString& oldkey, const ByteString& newkey);
 
   const_iterator begin() const { return m_Map.begin(); }
   const_iterator end() const { return m_Map.end(); }
 
-  CFX_WeakPtr<CFX_ByteStringPool> GetByteStringPool() const { return m_pPool; }
+  CFX_WeakPtr<ByteStringPool> GetByteStringPool() const { return m_pPool; }
 
  protected:
-  CFX_ByteString MaybeIntern(const CFX_ByteString& str);
+  ByteString MaybeIntern(const ByteString& str);
   std::unique_ptr<CPDF_Object> CloneNonCyclic(
       bool bDirect,
       std::set<const CPDF_Object*>* visited) const override;
 
-  CFX_WeakPtr<CFX_ByteStringPool> m_pPool;
-  std::map<CFX_ByteString, std::unique_ptr<CPDF_Object>> m_Map;
+  CFX_WeakPtr<ByteStringPool> m_pPool;
+  std::map<ByteString, std::unique_ptr<CPDF_Object>> m_Map;
 };
 
 inline CPDF_Dictionary* ToDictionary(CPDF_Object* obj) {
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index 47155176ae..f47551f82b 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -217,8 +217,8 @@ void InsertWidthArray(HDC hDC, int start, int end, CPDF_Array* pWidthArray) {
   InsertWidthArrayImpl(widths, size, pWidthArray);
 }
 
-CFX_ByteString FPDF_GetPSNameFromTT(HDC hDC) {
-  CFX_ByteString result;
+ByteString FPDF_GetPSNameFromTT(HDC hDC) {
+  ByteString result;
   DWORD size = ::GetFontData(hDC, 'eman', 0, nullptr, 0);
   if (size != GDI_ERROR) {
     LPBYTE buffer = FX_Alloc(BYTE, size);
@@ -299,7 +299,7 @@ int CalculateFlags(bool bold,
 void ProcessNonbCJK(CPDF_Dictionary* pBaseDict,
                     bool bold,
                     bool italic,
-                    CFX_ByteString basefont,
+                    ByteString basefont,
                     std::unique_ptr<CPDF_Array> pWidths) {
   if (bold && italic)
     basefont += ",BoldItalic";
@@ -316,7 +316,7 @@ void ProcessNonbCJK(CPDF_Dictionary* pBaseDict,
 
 std::unique_ptr<CPDF_Dictionary> CalculateFontDesc(
     CPDF_Document* pDoc,
-    CFX_ByteString basefont,
+    ByteString basefont,
     int flags,
     int italicangle,
     int ascend,
@@ -769,7 +769,7 @@ void CPDF_Document::DeletePage(int iPage) {
 
 CPDF_Font* CPDF_Document::AddStandardFont(const char* font,
                                           CPDF_FontEncoding* pEncoding) {
-  CFX_ByteString name(font);
+  ByteString name(font);
   if (PDF_GetStandardFontName(&name) < 0)
     return nullptr;
   return GetPageData()->GetStandardFont(name, pEncoding);
@@ -793,7 +793,7 @@ size_t CPDF_Document::CalculateEncodingDict(int charset,
 
   const uint16_t* pUnicodes = g_FX_CharsetUnicodes[i].m_pUnicodes;
   for (int j = 0; j < 128; j++) {
-    CFX_ByteString name = PDF_AdobeNameFromUnicode(pUnicodes[j]);
+    ByteString name = PDF_AdobeNameFromUnicode(pUnicodes[j]);
     pArray->AddNew<CPDF_Name>(name.IsEmpty() ? ".notdef" : name);
   }
   pBaseDict->SetNewFor<CPDF_Reference>("Encoding", this,
@@ -805,11 +805,11 @@ CPDF_Dictionary* CPDF_Document::ProcessbCJK(
     CPDF_Dictionary* pBaseDict,
     int charset,
     bool bVert,
-    CFX_ByteString basefont,
+    ByteString basefont,
     std::function<void(wchar_t, wchar_t, CPDF_Array*)> Insert) {
   CPDF_Dictionary* pFontDict = NewIndirect<CPDF_Dictionary>();
-  CFX_ByteString cmap;
-  CFX_ByteString ordering;
+  ByteString cmap;
+  ByteString ordering;
   int supplement = 0;
   CPDF_Array* pWidthArray = pFontDict->SetNewFor<CPDF_Array>("W");
   switch (charset) {
@@ -875,7 +875,7 @@ CPDF_Font* CPDF_Document::AddFont(CFX_Font* pFont, int charset, bool bVert) {
   bool bCJK = charset == FX_CHARSET_ChineseTraditional ||
               charset == FX_CHARSET_ChineseSimplified ||
               charset == FX_CHARSET_Hangul || charset == FX_CHARSET_ShiftJIS;
-  CFX_ByteString basefont = pFont->GetFamilyName();
+  ByteString basefont = pFont->GetFamilyName();
   basefont.Replace(" ", "");
   int flags =
       CalculateFlags(pFont->IsBold(), pFont->IsItalic(), pFont->IsFixedWidth(),
@@ -958,12 +958,12 @@ CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTW* pLogFont,
                                          bool bTranslateName) {
   LOGFONTA lfa;
   memcpy(&lfa, pLogFont, (char*)lfa.lfFaceName - (char*)&lfa);
-  CFX_ByteString face = CFX_ByteString::FromUnicode(pLogFont->lfFaceName);
+  ByteString face = ByteString::FromUnicode(pLogFont->lfFaceName);
   if (face.GetLength() >= LF_FACESIZE)
     return nullptr;
 
   strncpy(lfa.lfFaceName, face.c_str(),
-          (face.GetLength() + 1) * sizeof(CFX_ByteString::CharType));
+          (face.GetLength() + 1) * sizeof(ByteString::CharType));
   return AddWindowsFont(&lfa, bVert, bTranslateName);
 }
 
@@ -996,7 +996,7 @@ CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTA* pLogFont,
               pLogFont->lfCharSet == FX_CHARSET_ChineseSimplified ||
               pLogFont->lfCharSet == FX_CHARSET_Hangul ||
               pLogFont->lfCharSet == FX_CHARSET_ShiftJIS;
-  CFX_ByteString basefont;
+  ByteString basefont;
   if (bTranslateName && bCJK)
     basefont = FPDF_GetPSNameFromTT(hDC);
 
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index cc5076379e..ff80fa85c3 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -122,7 +122,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
       CPDF_Dictionary* pBaseDict,
       int charset,
       bool bVert,
-      CFX_ByteString basefont,
+      ByteString basefont,
       std::function<void(wchar_t, wchar_t, CPDF_Array*)> Insert);
   bool InsertDeletePDFPage(CPDF_Dictionary* pPages,
                            int nPagesToGo,
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp b/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
index 434470abeb..2a57411368 100644
--- a/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
@@ -23,7 +23,7 @@ CPDF_Object* FilterInvalidObjNum(CPDF_Object* obj) {
 
 CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder()
     : m_LastObjNum(0),
-      m_pByteStringPool(pdfium::MakeUnique<CFX_ByteStringPool>()) {}
+      m_pByteStringPool(pdfium::MakeUnique<ByteStringPool>()) {}
 
 CPDF_IndirectObjectHolder::~CPDF_IndirectObjectHolder() {
   m_pByteStringPool.DeleteObject();  // Make weak.
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder.h b/core/fpdfapi/parser/cpdf_indirect_object_holder.h
index b82377e5b7..ab99dd5fcc 100644
--- a/core/fpdfapi/parser/cpdf_indirect_object_holder.h
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder.h
@@ -58,7 +58,7 @@ class CPDF_IndirectObjectHolder {
   uint32_t GetLastObjNum() const { return m_LastObjNum; }
   void SetLastObjNum(uint32_t objnum) { m_LastObjNum = objnum; }
 
-  CFX_WeakPtr<CFX_ByteStringPool> GetByteStringPool() const {
+  CFX_WeakPtr<ByteStringPool> GetByteStringPool() const {
     return m_pByteStringPool;
   }
 
@@ -72,7 +72,7 @@ class CPDF_IndirectObjectHolder {
   uint32_t m_LastObjNum;
   std::map<uint32_t, std::unique_ptr<CPDF_Object>> m_IndirectObjs;
   std::vector<std::unique_ptr<CPDF_Object>> m_OrphanObjs;
-  CFX_WeakPtr<CFX_ByteStringPool> m_pByteStringPool;
+  CFX_WeakPtr<ByteStringPool> m_pByteStringPool;
 };
 
 #endif  // CORE_FPDFAPI_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_
diff --git a/core/fpdfapi/parser/cpdf_name.cpp b/core/fpdfapi/parser/cpdf_name.cpp
index ae33bc7fa0..0dd9890702 100644
--- a/core/fpdfapi/parser/cpdf_name.cpp
+++ b/core/fpdfapi/parser/cpdf_name.cpp
@@ -10,8 +10,7 @@
 #include "core/fxcrt/fx_stream.h"
 #include "third_party/base/ptr_util.h"
 
-CPDF_Name::CPDF_Name(CFX_WeakPtr<CFX_ByteStringPool> pPool,
-                     const CFX_ByteString& str)
+CPDF_Name::CPDF_Name(CFX_WeakPtr<ByteStringPool> pPool, const ByteString& str)
     : m_Name(str) {
   if (pPool)
     m_Name = pPool->Intern(m_Name);
@@ -27,11 +26,11 @@ std::unique_ptr<CPDF_Object> CPDF_Name::Clone() const {
   return pdfium::MakeUnique<CPDF_Name>(nullptr, m_Name);
 }
 
-CFX_ByteString CPDF_Name::GetString() const {
+ByteString CPDF_Name::GetString() const {
   return m_Name;
 }
 
-void CPDF_Name::SetString(const CFX_ByteString& str) {
+void CPDF_Name::SetString(const ByteString& str) {
   m_Name = str;
 }
 
@@ -47,11 +46,11 @@ const CPDF_Name* CPDF_Name::AsName() const {
   return this;
 }
 
-CFX_WideString CPDF_Name::GetUnicodeText() const {
+WideString CPDF_Name::GetUnicodeText() const {
   return PDF_DecodeText(m_Name);
 }
 
 bool CPDF_Name::WriteTo(IFX_ArchiveStream* archive) const {
   return archive->WriteString("/") &&
-         archive->WriteString(PDF_NameEncode(GetString()).AsStringC());
+         archive->WriteString(PDF_NameEncode(GetString()).AsStringView());
 }
diff --git a/core/fpdfapi/parser/cpdf_name.h b/core/fpdfapi/parser/cpdf_name.h
index 616f35f9bc..72a72a3a66 100644
--- a/core/fpdfapi/parser/cpdf_name.h
+++ b/core/fpdfapi/parser/cpdf_name.h
@@ -15,22 +15,22 @@
 
 class CPDF_Name : public CPDF_Object {
  public:
-  CPDF_Name(CFX_WeakPtr<CFX_ByteStringPool> pPool, const CFX_ByteString& str);
+  CPDF_Name(CFX_WeakPtr<ByteStringPool> pPool, const ByteString& str);
   ~CPDF_Name() override;
 
   // CPDF_Object:
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
-  CFX_ByteString GetString() const override;
-  CFX_WideString GetUnicodeText() const override;
-  void SetString(const CFX_ByteString& str) override;
+  ByteString GetString() const override;
+  WideString GetUnicodeText() const override;
+  void SetString(const ByteString& str) override;
   bool IsName() const override;
   CPDF_Name* AsName() override;
   const CPDF_Name* AsName() const override;
   bool WriteTo(IFX_ArchiveStream* archive) const override;
 
  protected:
-  CFX_ByteString m_Name;
+  ByteString m_Name;
 };
 
 inline CPDF_Name* ToName(CPDF_Object* obj) {
diff --git a/core/fpdfapi/parser/cpdf_number.cpp b/core/fpdfapi/parser/cpdf_number.cpp
index 9afe30adca..dac1f40b7f 100644
--- a/core/fpdfapi/parser/cpdf_number.cpp
+++ b/core/fpdfapi/parser/cpdf_number.cpp
@@ -14,7 +14,7 @@ CPDF_Number::CPDF_Number(int value) : m_bInteger(true), m_Integer(value) {}
 
 CPDF_Number::CPDF_Number(float value) : m_bInteger(false), m_Float(value) {}
 
-CPDF_Number::CPDF_Number(const CFX_ByteStringC& str)
+CPDF_Number::CPDF_Number(const ByteStringView& str)
     : m_bInteger(FX_atonum(str, &m_Integer)) {}
 
 CPDF_Number::~CPDF_Number() {}
@@ -48,16 +48,16 @@ const CPDF_Number* CPDF_Number::AsNumber() const {
   return this;
 }
 
-void CPDF_Number::SetString(const CFX_ByteString& str) {
-  m_bInteger = FX_atonum(str.AsStringC(), &m_Integer);
+void CPDF_Number::SetString(const ByteString& str) {
+  m_bInteger = FX_atonum(str.AsStringView(), &m_Integer);
 }
 
-CFX_ByteString CPDF_Number::GetString() const {
-  return m_bInteger ? CFX_ByteString::FormatInteger(m_Integer)
-                    : CFX_ByteString::FormatFloat(m_Float);
+ByteString CPDF_Number::GetString() const {
+  return m_bInteger ? ByteString::FormatInteger(m_Integer)
+                    : ByteString::FormatFloat(m_Float);
 }
 
 bool CPDF_Number::WriteTo(IFX_ArchiveStream* archive) const {
   return archive->WriteString(" ") &&
-         archive->WriteString(GetString().AsStringC());
+         archive->WriteString(GetString().AsStringView());
 }
diff --git a/core/fpdfapi/parser/cpdf_number.h b/core/fpdfapi/parser/cpdf_number.h
index 57f82274cb..661177363b 100644
--- a/core/fpdfapi/parser/cpdf_number.h
+++ b/core/fpdfapi/parser/cpdf_number.h
@@ -18,16 +18,16 @@ class CPDF_Number : public CPDF_Object {
   CPDF_Number();
   explicit CPDF_Number(int value);
   explicit CPDF_Number(float value);
-  explicit CPDF_Number(const CFX_ByteStringC& str);
+  explicit CPDF_Number(const ByteStringView& str);
   ~CPDF_Number() override;
 
   // CPDF_Object:
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
-  CFX_ByteString GetString() const override;
+  ByteString GetString() const override;
   float GetNumber() const override;
   int GetInteger() const override;
-  void SetString(const CFX_ByteString& str) override;
+  void SetString(const ByteString& str) override;
   bool IsNumber() const override;
   CPDF_Number* AsNumber() override;
   const CPDF_Number* AsNumber() const override;
diff --git a/core/fpdfapi/parser/cpdf_object.cpp b/core/fpdfapi/parser/cpdf_object.cpp
index b35c6e5b6f..67632a040c 100644
--- a/core/fpdfapi/parser/cpdf_object.cpp
+++ b/core/fpdfapi/parser/cpdf_object.cpp
@@ -39,12 +39,12 @@ std::unique_ptr<CPDF_Object> CPDF_Object::CloneNonCyclic(
   return Clone();
 }
 
-CFX_ByteString CPDF_Object::GetString() const {
-  return CFX_ByteString();
+ByteString CPDF_Object::GetString() const {
+  return ByteString();
 }
 
-CFX_WideString CPDF_Object::GetUnicodeText() const {
-  return CFX_WideString();
+WideString CPDF_Object::GetUnicodeText() const {
+  return WideString();
 }
 
 float CPDF_Object::GetNumber() const {
@@ -59,7 +59,7 @@ CPDF_Dictionary* CPDF_Object::GetDict() const {
   return nullptr;
 }
 
-void CPDF_Object::SetString(const CFX_ByteString& str) {
+void CPDF_Object::SetString(const ByteString& str) {
   NOTREACHED();
 }
 
diff --git a/core/fpdfapi/parser/cpdf_object.h b/core/fpdfapi/parser/cpdf_object.h
index a07ba677e8..4d4279f98a 100644
--- a/core/fpdfapi/parser/cpdf_object.h
+++ b/core/fpdfapi/parser/cpdf_object.h
@@ -55,13 +55,13 @@ class CPDF_Object {
   virtual std::unique_ptr<CPDF_Object> CloneDirectObject() const;
 
   virtual CPDF_Object* GetDirect() const;
-  virtual CFX_ByteString GetString() const;
-  virtual CFX_WideString GetUnicodeText() const;
+  virtual ByteString GetString() const;
+  virtual WideString GetUnicodeText() const;
   virtual float GetNumber() const;
   virtual int GetInteger() const;
   virtual CPDF_Dictionary* GetDict() const;
 
-  virtual void SetString(const CFX_ByteString& str);
+  virtual void SetString(const ByteString& str);
 
   virtual bool IsArray() const;
   virtual bool IsBoolean() const;
diff --git a/core/fpdfapi/parser/cpdf_object_walker.cpp b/core/fpdfapi/parser/cpdf_object_walker.cpp
index c6e0f0091d..cb59a05d06 100644
--- a/core/fpdfapi/parser/cpdf_object_walker.cpp
+++ b/core/fpdfapi/parser/cpdf_object_walker.cpp
@@ -57,11 +57,11 @@ class DictionaryIterator : public CPDF_ObjectWalker::SubobjectIterator {
     dict_iterator_ = object()->GetDict()->begin();
   }
 
-  const CFX_ByteString& dict_key() const { return dict_key_; }
+  const ByteString& dict_key() const { return dict_key_; }
 
  private:
   CPDF_Dictionary::const_iterator dict_iterator_;
-  CFX_ByteString dict_key_;
+  ByteString dict_key_;
 };
 
 class ArrayIterator : public CPDF_ObjectWalker::SubobjectIterator {
@@ -149,11 +149,11 @@ const CPDF_Object* CPDF_ObjectWalker::GetNext() {
       parent_object_ = it->object();
       dict_key_ = parent_object_->IsDictionary()
                       ? static_cast<DictionaryIterator*>(it)->dict_key()
-                      : CFX_ByteString();
+                      : ByteString();
       current_depth_ = stack_.size();
     }
   }
-  dict_key_ = CFX_ByteString();
+  dict_key_ = ByteString();
   current_depth_ = 0;
   return nullptr;
 }
diff --git a/core/fpdfapi/parser/cpdf_object_walker.h b/core/fpdfapi/parser/cpdf_object_walker.h
index 5590440f8f..8cad3c32f3 100644
--- a/core/fpdfapi/parser/cpdf_object_walker.h
+++ b/core/fpdfapi/parser/cpdf_object_walker.h
@@ -41,7 +41,7 @@ class CPDF_ObjectWalker {
 
   size_t current_depth() const { return current_depth_; }
   const CPDF_Object* GetParent() const { return parent_object_; }
-  const CFX_ByteString& dictionary_key() const { return dict_key_; }
+  const ByteString& dictionary_key() const { return dict_key_; }
 
  private:
   static std::unique_ptr<SubobjectIterator> MakeIterator(
@@ -50,7 +50,7 @@ class CPDF_ObjectWalker {
   const CPDF_Object* next_object_;
   const CPDF_Object* parent_object_;
 
-  CFX_ByteString dict_key_;
+  ByteString dict_key_;
   size_t current_depth_;
 
   std::stack<std::unique_ptr<SubobjectIterator>> stack_;
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index a9cad02f5e..b0a8126a3d 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -239,7 +239,7 @@ CPDF_Parser::Error CPDF_Parser::StartParseInternal(CPDF_Document* pDocument) {
     m_pSyntax->GetKeyword();
 
     bool bNumber;
-    CFX_ByteString xrefpos_str = m_pSyntax->GetNextWord(&bNumber);
+    ByteString xrefpos_str = m_pSyntax->GetNextWord(&bNumber);
     if (!bNumber)
       return FORMAT_ERROR;
 
@@ -314,7 +314,7 @@ CPDF_Parser::Error CPDF_Parser::SetEncryptHandler() {
   }
 
   if (m_pEncryptDict) {
-    CFX_ByteString filter = m_pEncryptDict->GetStringFor("Filter");
+    ByteString filter = m_pEncryptDict->GetStringFor("Filter");
     if (filter != "Standard")
       return HANDLER_ERROR;
 
@@ -364,7 +364,7 @@ bool CPDF_Parser::VerifyCrossRefV4() {
     FX_FILESIZE SavedPos = m_pSyntax->GetPos();
     m_pSyntax->SetPos(it.second.pos);
     bool is_num = false;
-    CFX_ByteString num_str = m_pSyntax->GetNextWord(&is_num);
+    ByteString num_str = m_pSyntax->GetNextWord(&is_num);
     m_pSyntax->SetPos(SavedPos);
     if (!is_num || num_str.IsEmpty() ||
         FXSYS_atoui(num_str.c_str()) != it.first) {
@@ -593,7 +593,7 @@ bool CPDF_Parser::ParseCrossRefV4(std::vector<CrossRefObjData>* out_objects) {
   while (1) {
     FX_FILESIZE SavedPos = m_pSyntax->GetPos();
     bool bIsNumber;
-    CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+    ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
     if (word.IsEmpty()) {
       return false;
     }
@@ -884,7 +884,7 @@ bool CPDF_Parser::RebuildCrossRef() {
                            m_ObjectInfo[pRef->GetRefObjNum()].pos != 0)) {
                         auto it = pTrailer->begin();
                         while (it != pTrailer->end()) {
-                          const CFX_ByteString& key = it->first;
+                          const ByteString& key = it->first;
                           CPDF_Object* pElement = it->second.get();
                           ++it;
                           uint32_t dwObjNum =
@@ -903,11 +903,10 @@ bool CPDF_Parser::RebuildCrossRef() {
                                                         : std::move(pObj)));
 
                       FX_FILESIZE dwSavePos = m_pSyntax->GetPos();
-                      CFX_ByteString strWord = m_pSyntax->GetKeyword();
+                      ByteString strWord = m_pSyntax->GetKeyword();
                       if (!strWord.Compare("startxref")) {
                         bool bNumber;
-                        CFX_ByteString bsOffset =
-                            m_pSyntax->GetNextWord(&bNumber);
+                        ByteString bsOffset = m_pSyntax->GetNextWord(&bNumber);
                         if (bNumber)
                           m_LastXRefOffset = FXSYS_atoi(bsOffset.c_str());
                       }
@@ -1316,7 +1315,7 @@ bool CPDF_Parser::ParseLinearizedHeader() {
 
   FX_FILESIZE SavedPos = m_pSyntax->GetPos();
   bool bIsNumber;
-  CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+  ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
   if (!bIsNumber)
     return false;
 
diff --git a/core/fpdfapi/parser/cpdf_parser.h b/core/fpdfapi/parser/cpdf_parser.h
index b4d0bee329..20bd6be9b4 100644
--- a/core/fpdfapi/parser/cpdf_parser.h
+++ b/core/fpdfapi/parser/cpdf_parser.h
@@ -63,7 +63,7 @@ class CPDF_Parser {
                              CPDF_Document* pDocument);
 
   void SetPassword(const char* password) { m_Password = password; }
-  CFX_ByteString GetPassword() { return m_Password; }
+  ByteString GetPassword() { return m_Password; }
   CPDF_Dictionary* GetTrailer() const;
   FX_FILESIZE GetLastXRefOffset() const { return m_LastXRefOffset; }
 
@@ -199,7 +199,7 @@ class CPDF_Parser {
   CFX_UnownedPtr<CPDF_Dictionary> m_pEncryptDict;
   FX_FILESIZE m_LastXRefOffset;
   std::unique_ptr<CPDF_SecurityHandler> m_pSecurityHandler;
-  CFX_ByteString m_Password;
+  ByteString m_Password;
   std::unique_ptr<TrailerData> m_TrailerData;
   std::unique_ptr<CPDF_LinearizedHeader> m_pLinearized;
   uint32_t m_dwLinearizedFirstPageXRefStartObjNum;
diff --git a/core/fpdfapi/parser/cpdf_reference.cpp b/core/fpdfapi/parser/cpdf_reference.cpp
index ce4c308d8c..2ca0bddc4f 100644
--- a/core/fpdfapi/parser/cpdf_reference.cpp
+++ b/core/fpdfapi/parser/cpdf_reference.cpp
@@ -20,9 +20,9 @@ CPDF_Object::Type CPDF_Reference::GetType() const {
   return REFERENCE;
 }
 
-CFX_ByteString CPDF_Reference::GetString() const {
+ByteString CPDF_Reference::GetString() const {
   CPDF_Object* obj = SafeGetDirect();
-  return obj ? obj->GetString() : CFX_ByteString();
+  return obj ? obj->GetString() : ByteString();
 }
 
 float CPDF_Reference::GetNumber() const {
diff --git a/core/fpdfapi/parser/cpdf_reference.h b/core/fpdfapi/parser/cpdf_reference.h
index ab160302fe..f564ab5b9b 100644
--- a/core/fpdfapi/parser/cpdf_reference.h
+++ b/core/fpdfapi/parser/cpdf_reference.h
@@ -24,7 +24,7 @@ class CPDF_Reference : public CPDF_Object {
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
   CPDF_Object* GetDirect() const override;
-  CFX_ByteString GetString() const override;
+  ByteString GetString() const override;
   float GetNumber() const override;
   int GetInteger() const override;
   CPDF_Dictionary* GetDict() const override;
diff --git a/core/fpdfapi/parser/cpdf_security_handler.cpp b/core/fpdfapi/parser/cpdf_security_handler.cpp
index 03b90abf4a..b838e9cf05 100644
--- a/core/fpdfapi/parser/cpdf_security_handler.cpp
+++ b/core/fpdfapi/parser/cpdf_security_handler.cpp
@@ -42,12 +42,12 @@ void CalcEncryptKey(CPDF_Dictionary* pEncrypt,
   CRYPT_md5_context md5;
   CRYPT_MD5Start(&md5);
   CRYPT_MD5Update(&md5, passcode, 32);
-  CFX_ByteString okey = pEncrypt->GetStringFor("O");
+  ByteString okey = pEncrypt->GetStringFor("O");
   CRYPT_MD5Update(&md5, (uint8_t*)okey.c_str(), okey.GetLength());
   uint32_t perm = pEncrypt->GetIntegerFor("P");
   CRYPT_MD5Update(&md5, (uint8_t*)&perm, 4);
   if (pIdArray) {
-    CFX_ByteString id = pIdArray->GetStringAt(0);
+    ByteString id = pIdArray->GetStringAt(0);
     CRYPT_MD5Update(&md5, (uint8_t*)id.c_str(), id.GetLength());
   }
   if (!bIgnoreMeta && revision >= 3 &&
@@ -97,7 +97,7 @@ bool CPDF_SecurityHandler::OnInit(CPDF_Parser* pParser,
 }
 
 bool CPDF_SecurityHandler::CheckSecurity(int32_t key_len) {
-  CFX_ByteString password = m_pParser->GetPassword();
+  ByteString password = m_pParser->GetPassword();
   if (!password.IsEmpty() &&
       CheckPassword(password.raw_str(), password.GetLength(), true,
                     m_EncryptKey, key_len)) {
@@ -113,7 +113,7 @@ uint32_t CPDF_SecurityHandler::GetPermissions() {
 }
 
 static bool LoadCryptInfo(CPDF_Dictionary* pEncryptDict,
-                          const CFX_ByteString& name,
+                          const ByteString& name,
                           int& cipher,
                           int& keylen) {
   int Version = pEncryptDict->GetIntegerFor("V");
@@ -144,7 +144,7 @@ static bool LoadCryptInfo(CPDF_Dictionary* pEncryptDict,
         nKeyBits *= 8;
       }
       keylen = nKeyBits / 8;
-      CFX_ByteString cipher_name = pDefFilter->GetStringFor("CFM");
+      ByteString cipher_name = pDefFilter->GetStringFor("CFM");
       if (cipher_name == "AESV2" || cipher_name == "AESV3") {
         cipher = FXCIPHER_AES;
       }
@@ -164,10 +164,10 @@ bool CPDF_SecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict) {
   m_Revision = pEncryptDict->GetIntegerFor("R");
   m_Permissions = pEncryptDict->GetIntegerFor("P", -1);
   if (m_Version < 4)
-    return LoadCryptInfo(pEncryptDict, CFX_ByteString(), m_Cipher, m_KeyLen);
+    return LoadCryptInfo(pEncryptDict, ByteString(), m_Cipher, m_KeyLen);
 
-  CFX_ByteString stmf_name = pEncryptDict->GetStringFor("StmF");
-  CFX_ByteString strf_name = pEncryptDict->GetStringFor("StrF");
+  ByteString stmf_name = pEncryptDict->GetStringFor("StmF");
+  ByteString strf_name = pEncryptDict->GetStringFor("StrF");
   if (stmf_name != strf_name)
     return false;
 
@@ -183,8 +183,8 @@ bool CPDF_SecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict,
   m_Revision = pEncryptDict->GetIntegerFor("R");
   m_Permissions = pEncryptDict->GetIntegerFor("P", -1);
 
-  CFX_ByteString strf_name;
-  CFX_ByteString stmf_name;
+  ByteString strf_name;
+  ByteString stmf_name;
   if (m_Version >= 4) {
     stmf_name = pEncryptDict->GetStringFor("StmF");
     strf_name = pEncryptDict->GetStringFor("StrF");
@@ -310,11 +310,11 @@ bool CPDF_SecurityHandler::AES256_CheckPassword(const uint8_t* password,
   if (!m_pEncryptDict)
     return false;
 
-  CFX_ByteString okey = m_pEncryptDict->GetStringFor("O");
+  ByteString okey = m_pEncryptDict->GetStringFor("O");
   if (okey.GetLength() < 48)
     return false;
 
-  CFX_ByteString ukey = m_pEncryptDict->GetStringFor("U");
+  ByteString ukey = m_pEncryptDict->GetStringFor("U");
   if (ukey.GetLength() < 48)
     return false;
 
@@ -351,9 +351,9 @@ bool CPDF_SecurityHandler::AES256_CheckPassword(const uint8_t* password,
 
     CRYPT_SHA256Finish(&sha, digest);
   }
-  CFX_ByteString ekey = m_pEncryptDict
-                            ? m_pEncryptDict->GetStringFor(bOwner ? "OE" : "UE")
-                            : CFX_ByteString();
+  ByteString ekey = m_pEncryptDict
+                        ? m_pEncryptDict->GetStringFor(bOwner ? "OE" : "UE")
+                        : ByteString();
   if (ekey.GetLength() < 32)
     return false;
 
@@ -366,7 +366,7 @@ bool CPDF_SecurityHandler::AES256_CheckPassword(const uint8_t* password,
   CRYPT_AESDecrypt(&aes, key, ekey.raw_str(), 32);
   CRYPT_AESSetKey(&aes, 16, key, 32, false);
   CRYPT_AESSetIV(&aes, iv);
-  CFX_ByteString perms = m_pEncryptDict->GetStringFor("Perms");
+  ByteString perms = m_pEncryptDict->GetStringFor("Perms");
   if (perms.IsEmpty())
     return false;
 
@@ -415,8 +415,8 @@ bool CPDF_SecurityHandler::CheckUserPassword(const uint8_t* password,
                                              int32_t key_len) {
   CalcEncryptKey(m_pEncryptDict.Get(), password, pass_size, key, key_len,
                  bIgnoreEncryptMeta, m_pParser->GetIDArray());
-  CFX_ByteString ukey =
-      m_pEncryptDict ? m_pEncryptDict->GetStringFor("U") : CFX_ByteString();
+  ByteString ukey =
+      m_pEncryptDict ? m_pEncryptDict->GetStringFor("U") : ByteString();
   if (ukey.GetLength() < 16) {
     return false;
   }
@@ -443,7 +443,7 @@ bool CPDF_SecurityHandler::CheckUserPassword(const uint8_t* password,
     CRYPT_MD5Update(&md5, defpasscode, 32);
     CPDF_Array* pIdArray = m_pParser->GetIDArray();
     if (pIdArray) {
-      CFX_ByteString id = pIdArray->GetStringAt(0);
+      ByteString id = pIdArray->GetStringAt(0);
       CRYPT_MD5Update(&md5, (uint8_t*)id.c_str(), id.GetLength());
     }
     CRYPT_MD5Finish(&md5, ukeybuf);
@@ -452,10 +452,10 @@ bool CPDF_SecurityHandler::CheckUserPassword(const uint8_t* password,
   return memcmp(ukey.c_str(), ukeybuf, 16) == 0;
 }
 
-CFX_ByteString CPDF_SecurityHandler::GetUserPassword(const uint8_t* owner_pass,
-                                                     uint32_t pass_size,
-                                                     int32_t key_len) {
-  CFX_ByteString okey = m_pEncryptDict->GetStringFor("O");
+ByteString CPDF_SecurityHandler::GetUserPassword(const uint8_t* owner_pass,
+                                                 uint32_t pass_size,
+                                                 int32_t key_len) {
+  ByteString okey = m_pEncryptDict->GetStringFor("O");
   uint8_t passcode[32];
   for (uint32_t i = 0; i < 32; i++) {
     passcode[i] = i < pass_size ? owner_pass[i] : defpasscode[i - pass_size];
@@ -496,13 +496,13 @@ CFX_ByteString CPDF_SecurityHandler::GetUserPassword(const uint8_t* owner_pass,
   while (len && defpasscode[len - 1] == okeybuf[len - 1]) {
     len--;
   }
-  return CFX_ByteString(okeybuf, len);
+  return ByteString(okeybuf, len);
 }
 bool CPDF_SecurityHandler::CheckOwnerPassword(const uint8_t* password,
                                               uint32_t pass_size,
                                               uint8_t* key,
                                               int32_t key_len) {
-  CFX_ByteString user_pass = GetUserPassword(password, pass_size, key_len);
+  ByteString user_pass = GetUserPassword(password, pass_size, key_len);
   if (CheckUserPassword(user_pass.raw_str(), user_pass.GetLength(), false, key,
                         key_len)) {
     return true;
@@ -575,8 +575,7 @@ void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
         CRYPT_ArcFourCryptBlock(passcode, 32, tempkey, key_len);
       }
     }
-    pEncryptDict->SetNewFor<CPDF_String>("O", CFX_ByteString(passcode, 32),
-                                         false);
+    pEncryptDict->SetNewFor<CPDF_String>("O", ByteString(passcode, 32), false);
   }
   CalcEncryptKey(m_pEncryptDict.Get(), (uint8_t*)user_pass, user_size,
                  m_EncryptKey, key_len, false, pIdArray);
@@ -584,14 +583,13 @@ void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
     uint8_t tempbuf[32];
     memcpy(tempbuf, defpasscode, 32);
     CRYPT_ArcFourCryptBlock(tempbuf, 32, m_EncryptKey, key_len);
-    pEncryptDict->SetNewFor<CPDF_String>("U", CFX_ByteString(tempbuf, 32),
-                                         false);
+    pEncryptDict->SetNewFor<CPDF_String>("U", ByteString(tempbuf, 32), false);
   } else {
     CRYPT_md5_context md5;
     CRYPT_MD5Start(&md5);
     CRYPT_MD5Update(&md5, defpasscode, 32);
     if (pIdArray) {
-      CFX_ByteString id = pIdArray->GetStringAt(0);
+      ByteString id = pIdArray->GetStringAt(0);
       CRYPT_MD5Update(&md5, (uint8_t*)id.c_str(), id.GetLength());
     }
     uint8_t digest[32];
@@ -605,8 +603,7 @@ void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
       CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len);
     }
     CRYPT_MD5Generate(digest, 16, digest + 16);
-    pEncryptDict->SetNewFor<CPDF_String>("U", CFX_ByteString(digest, 32),
-                                         false);
+    pEncryptDict->SetNewFor<CPDF_String>("U", ByteString(digest, 32), false);
   }
 }
 void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
@@ -640,7 +637,7 @@ void CPDF_SecurityHandler::AES256_SetPassword(CPDF_Dictionary* pEncryptDict,
   uint8_t digest[20];
   CRYPT_SHA1Finish(&sha, digest);
 
-  CFX_ByteString ukey = pEncryptDict->GetStringFor("U");
+  ByteString ukey = pEncryptDict->GetStringFor("U");
   CRYPT_sha2_context sha2;
   uint8_t digest1[48];
   if (m_Revision >= 6) {
@@ -657,7 +654,7 @@ void CPDF_SecurityHandler::AES256_SetPassword(CPDF_Dictionary* pEncryptDict,
   }
   memcpy(digest1 + 32, digest, 16);
   pEncryptDict->SetNewFor<CPDF_String>(bOwner ? "O" : "U",
-                                       CFX_ByteString(digest1, 48), false);
+                                       ByteString(digest1, 48), false);
   if (m_Revision >= 6) {
     Revision6_Hash(password, size, digest + 8,
                    bOwner ? ukey.raw_str() : nullptr, digest1);
@@ -678,7 +675,7 @@ void CPDF_SecurityHandler::AES256_SetPassword(CPDF_Dictionary* pEncryptDict,
   CRYPT_AESSetIV(&aes, iv);
   CRYPT_AESEncrypt(&aes, digest1, key, 32);
   pEncryptDict->SetNewFor<CPDF_String>(bOwner ? "OE" : "UE",
-                                       CFX_ByteString(digest1, 32), false);
+                                       ByteString(digest1, 32), false);
 }
 
 void CPDF_SecurityHandler::AES256_SetPerms(CPDF_Dictionary* pEncryptDict,
@@ -709,6 +706,5 @@ void CPDF_SecurityHandler::AES256_SetPerms(CPDF_Dictionary* pEncryptDict,
 
   uint8_t buf1[16];
   CRYPT_AESEncrypt(&aes, buf1, buf, 16);
-  pEncryptDict->SetNewFor<CPDF_String>("Perms", CFX_ByteString(buf1, 16),
-                                       false);
+  pEncryptDict->SetNewFor<CPDF_String>("Perms", ByteString(buf1, 16), false);
 }
diff --git a/core/fpdfapi/parser/cpdf_security_handler.h b/core/fpdfapi/parser/cpdf_security_handler.h
index 27f7f7c610..eb7d13f2e6 100644
--- a/core/fpdfapi/parser/cpdf_security_handler.h
+++ b/core/fpdfapi/parser/cpdf_security_handler.h
@@ -46,9 +46,9 @@ class CPDF_SecurityHandler {
                 uint32_t user_size,
                 uint32_t type = PDF_ENCRYPT_CONTENT);
 
-  CFX_ByteString GetUserPassword(const uint8_t* owner_pass,
-                                 uint32_t pass_size,
-                                 int32_t key_len);
+  ByteString GetUserPassword(const uint8_t* owner_pass,
+                             uint32_t pass_size,
+                             int32_t key_len);
   bool CheckPassword(const uint8_t* password,
                      uint32_t pass_size,
                      bool bOwner,
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.cpp b/core/fpdfapi/parser/cpdf_simple_parser.cpp
index 650c216e05..d800796d58 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_simple_parser.cpp
@@ -11,7 +11,7 @@
 CPDF_SimpleParser::CPDF_SimpleParser(const uint8_t* pData, uint32_t dwSize)
     : m_pData(pData), m_dwSize(dwSize), m_dwCurPos(0) {}
 
-CPDF_SimpleParser::CPDF_SimpleParser(const CFX_ByteStringC& str)
+CPDF_SimpleParser::CPDF_SimpleParser(const ByteStringView& str)
     : m_pData(str.raw_str()), m_dwSize(str.GetLength()), m_dwCurPos(0) {}
 
 void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
@@ -91,7 +91,7 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
   }
 }
 
-CFX_ByteStringC CPDF_SimpleParser::GetWord() {
+ByteStringView CPDF_SimpleParser::GetWord() {
   const uint8_t* pStart;
   uint32_t dwSize;
   ParseWord(pStart, dwSize);
@@ -102,8 +102,8 @@ CFX_ByteStringC CPDF_SimpleParser::GetWord() {
     if (m_dwCurPos < m_dwSize) {
       m_dwCurPos++;
     }
-    return CFX_ByteStringC(pStart,
-                           (FX_STRSIZE)(m_dwCurPos - (pStart - m_pData)));
+    return ByteStringView(pStart,
+                          (FX_STRSIZE)(m_dwCurPos - (pStart - m_pData)));
   }
   if (dwSize == 1 && pStart[0] == '(') {
     int level = 1;
@@ -130,13 +130,13 @@ CFX_ByteStringC CPDF_SimpleParser::GetWord() {
     if (m_dwCurPos < m_dwSize) {
       m_dwCurPos++;
     }
-    return CFX_ByteStringC(pStart,
-                           (FX_STRSIZE)(m_dwCurPos - (pStart - m_pData)));
+    return ByteStringView(pStart,
+                          (FX_STRSIZE)(m_dwCurPos - (pStart - m_pData)));
   }
-  return CFX_ByteStringC(pStart, dwSize);
+  return ByteStringView(pStart, dwSize);
 }
 
-bool CPDF_SimpleParser::FindTagParamFromStart(const CFX_ByteStringC& token,
+bool CPDF_SimpleParser::FindTagParamFromStart(const ByteStringView& token,
                                               int nParams) {
   nParams++;
   uint32_t* pBuf = FX_Alloc(uint32_t, nParams);
@@ -152,7 +152,7 @@ bool CPDF_SimpleParser::FindTagParamFromStart(const CFX_ByteStringC& token,
     if (buf_count > nParams) {
       buf_count = nParams;
     }
-    CFX_ByteStringC word = GetWord();
+    ByteStringView word = GetWord();
     if (word.IsEmpty()) {
       FX_Free(pBuf);
       return false;
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.h b/core/fpdfapi/parser/cpdf_simple_parser.h
index 0ff6985660..72cf700f60 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser.h
+++ b/core/fpdfapi/parser/cpdf_simple_parser.h
@@ -13,13 +13,13 @@
 class CPDF_SimpleParser {
  public:
   CPDF_SimpleParser(const uint8_t* pData, uint32_t dwSize);
-  explicit CPDF_SimpleParser(const CFX_ByteStringC& str);
+  explicit CPDF_SimpleParser(const ByteStringView& str);
 
-  CFX_ByteStringC GetWord();
+  ByteStringView GetWord();
 
   // Find the token and its |nParams| parameters from the start of data,
   // and move the current position to the start of those parameters.
-  bool FindTagParamFromStart(const CFX_ByteStringC& token, int nParams);
+  bool FindTagParamFromStart(const ByteStringView& token, int nParams);
 
   // For testing only.
   uint32_t GetCurPos() const { return m_dwCurPos; }
diff --git a/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
index bdb532d3e0..a2f43386e7 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
@@ -50,7 +50,7 @@ TEST(SimpleParserTest, GetWord) {
   for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
     const pdfium::StrFuncTestData& data = test_data[i];
     CPDF_SimpleParser parser(data.input, data.input_size);
-    CFX_ByteStringC word = parser.GetWord();
+    ByteStringView word = parser.GetWord();
     EXPECT_EQ(std::string(reinterpret_cast<const char*>(data.expected),
                           data.expected_size),
               std::string(word.unterminated_c_str(), word.GetLength()))
diff --git a/core/fpdfapi/parser/cpdf_stream.cpp b/core/fpdfapi/parser/cpdf_stream.cpp
index fadaec1b7e..c00096df8b 100644
--- a/core/fpdfapi/parser/cpdf_stream.cpp
+++ b/core/fpdfapi/parser/cpdf_stream.cpp
@@ -145,7 +145,7 @@ bool CPDF_Stream::HasFilter() const {
   return m_pDict && m_pDict->KeyExist("Filter");
 }
 
-CFX_WideString CPDF_Stream::GetUnicodeText() const {
+WideString CPDF_Stream::GetUnicodeText() const {
   auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(this);
   pAcc->LoadAllData(false);
   return PDF_DecodeText(pAcc->GetData(), pAcc->GetSize());
diff --git a/core/fpdfapi/parser/cpdf_stream.h b/core/fpdfapi/parser/cpdf_stream.h
index 3c3b674a48..be70e05e72 100644
--- a/core/fpdfapi/parser/cpdf_stream.h
+++ b/core/fpdfapi/parser/cpdf_stream.h
@@ -30,7 +30,7 @@ class CPDF_Stream : public CPDF_Object {
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
   CPDF_Dictionary* GetDict() const override;
-  CFX_WideString GetUnicodeText() const override;
+  WideString GetUnicodeText() const override;
   bool IsStream() const override;
   CPDF_Stream* AsStream() override;
   const CPDF_Stream* AsStream() const override;
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.h b/core/fpdfapi/parser/cpdf_stream_acc.h
index bc03cb097b..2161dd1950 100644
--- a/core/fpdfapi/parser/cpdf_stream_acc.h
+++ b/core/fpdfapi/parser/cpdf_stream_acc.h
@@ -34,7 +34,7 @@ class CPDF_StreamAcc : public CFX_Retainable {
 
   const uint8_t* GetData() const;
   uint32_t GetSize() const;
-  const CFX_ByteString& GetImageDecoder() const { return m_ImageDecoder; }
+  const ByteString& GetImageDecoder() const { return m_ImageDecoder; }
   const CPDF_Dictionary* GetImageParam() const { return m_pImageParam; }
   std::unique_ptr<uint8_t, FxFreeDeleter> DetachData();
 
@@ -45,7 +45,7 @@ class CPDF_StreamAcc : public CFX_Retainable {
   uint8_t* m_pData;
   uint32_t m_dwSize;
   bool m_bNewBuf;
-  CFX_ByteString m_ImageDecoder;
+  ByteString m_ImageDecoder;
   CPDF_Dictionary* m_pImageParam;
   CFX_UnownedPtr<const CPDF_Stream> const m_pStream;
   uint8_t* m_pSrcData;
diff --git a/core/fpdfapi/parser/cpdf_string.cpp b/core/fpdfapi/parser/cpdf_string.cpp
index 6ce6bf3473..1539861622 100644
--- a/core/fpdfapi/parser/cpdf_string.cpp
+++ b/core/fpdfapi/parser/cpdf_string.cpp
@@ -14,16 +14,16 @@
 
 CPDF_String::CPDF_String() : m_bHex(false) {}
 
-CPDF_String::CPDF_String(CFX_WeakPtr<CFX_ByteStringPool> pPool,
-                         const CFX_ByteString& str,
+CPDF_String::CPDF_String(CFX_WeakPtr<ByteStringPool> pPool,
+                         const ByteString& str,
                          bool bHex)
     : m_String(str), m_bHex(bHex) {
   if (pPool)
     m_String = pPool->Intern(m_String);
 }
 
-CPDF_String::CPDF_String(CFX_WeakPtr<CFX_ByteStringPool> pPool,
-                         const CFX_WideString& str)
+CPDF_String::CPDF_String(CFX_WeakPtr<ByteStringPool> pPool,
+                         const WideString& str)
     : m_String(PDF_EncodeText(str)), m_bHex(false) {
   if (pPool)
     m_String = pPool->Intern(m_String);
@@ -42,11 +42,11 @@ std::unique_ptr<CPDF_Object> CPDF_String::Clone() const {
   return std::move(pRet);
 }
 
-CFX_ByteString CPDF_String::GetString() const {
+ByteString CPDF_String::GetString() const {
   return m_String;
 }
 
-void CPDF_String::SetString(const CFX_ByteString& str) {
+void CPDF_String::SetString(const ByteString& str) {
   m_String = str;
 }
 
@@ -62,11 +62,11 @@ const CPDF_String* CPDF_String::AsString() const {
   return this;
 }
 
-CFX_WideString CPDF_String::GetUnicodeText() const {
+WideString CPDF_String::GetUnicodeText() const {
   return PDF_DecodeText(m_String);
 }
 
 bool CPDF_String::WriteTo(IFX_ArchiveStream* archive) const {
   return archive->WriteString(
-      PDF_EncodeString(GetString(), IsHex()).AsStringC());
+      PDF_EncodeString(GetString(), IsHex()).AsStringView());
 }
diff --git a/core/fpdfapi/parser/cpdf_string.h b/core/fpdfapi/parser/cpdf_string.h
index ccd6f530c1..9fd3e6ae8a 100644
--- a/core/fpdfapi/parser/cpdf_string.h
+++ b/core/fpdfapi/parser/cpdf_string.h
@@ -18,18 +18,18 @@
 class CPDF_String : public CPDF_Object {
  public:
   CPDF_String();
-  CPDF_String(CFX_WeakPtr<CFX_ByteStringPool> pPool,
-              const CFX_ByteString& str,
+  CPDF_String(CFX_WeakPtr<ByteStringPool> pPool,
+              const ByteString& str,
               bool bHex);
-  CPDF_String(CFX_WeakPtr<CFX_ByteStringPool> pPool, const CFX_WideString& str);
+  CPDF_String(CFX_WeakPtr<ByteStringPool> pPool, const WideString& str);
   ~CPDF_String() override;
 
   // CPDF_Object:
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
-  CFX_ByteString GetString() const override;
-  CFX_WideString GetUnicodeText() const override;
-  void SetString(const CFX_ByteString& str) override;
+  ByteString GetString() const override;
+  WideString GetUnicodeText() const override;
+  void SetString(const ByteString& str) override;
   bool IsString() const override;
   CPDF_String* AsString() override;
   const CPDF_String* AsString() const override;
@@ -38,7 +38,7 @@ class CPDF_String : public CPDF_Object {
   bool IsHex() const { return m_bHex; }
 
  protected:
-  CFX_ByteString m_String;
+  ByteString m_String;
   bool m_bHex;
 };
 
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.cpp b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
index 779bf81e0f..4412105c7b 100644
--- a/core/fpdfapi/parser/cpdf_syntax_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
@@ -41,10 +41,9 @@ enum class ReadStatus { Normal, Backslash, Octal, FinishOctal, CarriageReturn };
 int CPDF_SyntaxParser::s_CurrentRecursionDepth = 0;
 
 CPDF_SyntaxParser::CPDF_SyntaxParser()
-    : CPDF_SyntaxParser(CFX_WeakPtr<CFX_ByteStringPool>()) {}
+    : CPDF_SyntaxParser(CFX_WeakPtr<ByteStringPool>()) {}
 
-CPDF_SyntaxParser::CPDF_SyntaxParser(
-    const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
+CPDF_SyntaxParser::CPDF_SyntaxParser(const CFX_WeakPtr<ByteStringPool>& pPool)
     : m_MetadataObjnum(0),
       m_pFileAccess(nullptr),
       m_pFileBuf(nullptr),
@@ -187,10 +186,10 @@ void CPDF_SyntaxParser::GetNextWordInternal(bool* bIsNumber) {
   }
 }
 
-CFX_ByteString CPDF_SyntaxParser::ReadString() {
+ByteString CPDF_SyntaxParser::ReadString() {
   uint8_t ch;
   if (!GetNextChar(ch))
-    return CFX_ByteString();
+    return ByteString();
 
   std::ostringstream buf;
   int32_t parlevel = 0;
@@ -201,7 +200,7 @@ CFX_ByteString CPDF_SyntaxParser::ReadString() {
       case ReadStatus::Normal:
         if (ch == ')') {
           if (parlevel == 0)
-            return CFX_ByteString(buf);
+            return ByteString(buf);
           parlevel--;
         } else if (ch == '(') {
           parlevel++;
@@ -270,13 +269,13 @@ CFX_ByteString CPDF_SyntaxParser::ReadString() {
   }
 
   GetNextChar(ch);
-  return CFX_ByteString(buf);
+  return ByteString(buf);
 }
 
-CFX_ByteString CPDF_SyntaxParser::ReadHexString() {
+ByteString CPDF_SyntaxParser::ReadHexString() {
   uint8_t ch;
   if (!GetNextChar(ch))
-    return CFX_ByteString();
+    return ByteString();
 
   std::ostringstream buf;
   bool bFirst = true;
@@ -302,7 +301,7 @@ CFX_ByteString CPDF_SyntaxParser::ReadHexString() {
   if (!bFirst)
     buf << static_cast<char>(code);
 
-  return CFX_ByteString(buf);
+  return ByteString(buf);
 }
 
 void CPDF_SyntaxParser::ToNextLine() {
@@ -344,20 +343,20 @@ void CPDF_SyntaxParser::ToNextWord() {
   m_Pos--;
 }
 
-CFX_ByteString CPDF_SyntaxParser::GetNextWord(bool* bIsNumber) {
+ByteString CPDF_SyntaxParser::GetNextWord(bool* bIsNumber) {
   const CPDF_ReadValidator::Session read_session(GetValidator().Get());
   GetNextWordInternal(bIsNumber);
   return GetValidator()->has_read_problems()
-             ? CFX_ByteString()
-             : CFX_ByteString((const char*)m_WordBuffer, m_WordSize);
+             ? ByteString()
+             : ByteString((const char*)m_WordBuffer, m_WordSize);
 }
 
-CFX_ByteString CPDF_SyntaxParser::PeekNextWord(bool* bIsNumber) {
+ByteString CPDF_SyntaxParser::PeekNextWord(bool* bIsNumber) {
   const CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos);
   return GetNextWord(bIsNumber);
 }
 
-CFX_ByteString CPDF_SyntaxParser::GetKeyword() {
+ByteString CPDF_SyntaxParser::GetKeyword() {
   return GetNextWord(nullptr);
 }
 
@@ -386,15 +385,15 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetObjectInternal(
 
   FX_FILESIZE SavedObjPos = m_Pos;
   bool bIsNumber;
-  CFX_ByteString word = GetNextWord(&bIsNumber);
+  ByteString word = GetNextWord(&bIsNumber);
   if (word.GetLength() == 0)
     return nullptr;
 
   if (bIsNumber) {
     FX_FILESIZE SavedPos = m_Pos;
-    CFX_ByteString nextword = GetNextWord(&bIsNumber);
+    ByteString nextword = GetNextWord(&bIsNumber);
     if (bIsNumber) {
-      CFX_ByteString nextword2 = GetNextWord(nullptr);
+      ByteString nextword2 = GetNextWord(nullptr);
       if (nextword2 == "R") {
         uint32_t refnum = FXSYS_atoui(word.c_str());
         if (refnum == CPDF_Object::kInvalidObjNum)
@@ -403,7 +402,7 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetObjectInternal(
       }
     }
     m_Pos = SavedPos;
-    return pdfium::MakeUnique<CPDF_Number>(word.AsStringC());
+    return pdfium::MakeUnique<CPDF_Number>(word.AsStringView());
   }
 
   if (word == "true" || word == "false")
@@ -413,13 +412,13 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetObjectInternal(
     return pdfium::MakeUnique<CPDF_Null>();
 
   if (word == "(") {
-    CFX_ByteString str = ReadString();
+    ByteString str = ReadString();
     if (m_pCryptoHandler && bDecrypt)
       str = m_pCryptoHandler->Decrypt(objnum, gennum, str);
     return pdfium::MakeUnique<CPDF_String>(m_pPool, str, false);
   }
   if (word == "<") {
-    CFX_ByteString str = ReadHexString();
+    ByteString str = ReadHexString();
     if (m_pCryptoHandler && bDecrypt)
       str = m_pCryptoHandler->Decrypt(objnum, gennum, str);
     return pdfium::MakeUnique<CPDF_String>(m_pPool, str, true);
@@ -437,14 +436,14 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetObjectInternal(
   if (word[0] == '/') {
     return pdfium::MakeUnique<CPDF_Name>(
         m_pPool,
-        PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1)));
+        PDF_NameDecode(ByteStringView(m_WordBuffer + 1, m_WordSize - 1)));
   }
   if (word == "<<") {
     FX_FILESIZE dwSignValuePos = 0;
     std::unique_ptr<CPDF_Dictionary> pDict =
         pdfium::MakeUnique<CPDF_Dictionary>(m_pPool);
     while (1) {
-      CFX_ByteString key = GetNextWord(nullptr);
+      ByteString key = GetNextWord(nullptr);
       if (key.IsEmpty())
         return nullptr;
 
@@ -477,7 +476,7 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetObjectInternal(
       }
 
       if (!key.IsEmpty()) {
-        CFX_ByteString keyNoSlash(key.raw_str() + 1, key.GetLength() - 1);
+        ByteString keyNoSlash(key.raw_str() + 1, key.GetLength() - 1);
         pDict->SetFor(keyNoSlash, std::move(pObj));
       }
     }
@@ -492,7 +491,7 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetObjectInternal(
     }
 
     FX_FILESIZE SavedPos = m_Pos;
-    CFX_ByteString nextword = GetNextWord(nullptr);
+    ByteString nextword = GetNextWord(nullptr);
     if (nextword != "stream") {
       m_Pos = SavedPos;
       return std::move(pDict);
@@ -526,7 +525,7 @@ std::unique_ptr<CPDF_Object> CPDF_SyntaxParser::GetIndirectObject(
   const CPDF_ReadValidator::Session read_session(GetValidator().Get());
   const FX_FILESIZE saved_pos = GetPos();
   bool is_number = false;
-  CFX_ByteString word = GetNextWord(&is_number);
+  ByteString word = GetNextWord(&is_number);
   if (!is_number || word.IsEmpty()) {
     SetPos(saved_pos);
     return nullptr;
@@ -588,8 +587,8 @@ std::unique_ptr<CPDF_Stream> CPDF_SyntaxParser::ReadStream(
   ToNextLine();
   FX_FILESIZE streamStartPos = m_Pos;
 
-  const CFX_ByteStringC kEndStreamStr("endstream");
-  const CFX_ByteStringC kEndObjStr("endobj");
+  const ByteStringView kEndStreamStr("endstream");
+  const ByteStringView kEndObjStr("endobj");
 
   CPDF_CryptoHandler* pCryptoHandler =
       objnum == m_MetadataObjnum ? nullptr : m_pCryptoHandler.Get();
@@ -757,7 +756,7 @@ uint32_t CPDF_SyntaxParser::GetDirectNum() {
 
 bool CPDF_SyntaxParser::IsWholeWord(FX_FILESIZE startpos,
                                     FX_FILESIZE limit,
-                                    const CFX_ByteStringC& tag,
+                                    const ByteStringView& tag,
                                     bool checkKeyword) {
   const uint32_t taglen = tag.GetLength();
 
@@ -783,7 +782,7 @@ bool CPDF_SyntaxParser::IsWholeWord(FX_FILESIZE startpos,
   return true;
 }
 
-bool CPDF_SyntaxParser::BackwardsSearchToWord(const CFX_ByteStringC& tag,
+bool CPDF_SyntaxParser::BackwardsSearchToWord(const ByteStringView& tag,
                                               FX_FILESIZE limit) {
   int32_t taglen = tag.GetLength();
   if (taglen == 0)
@@ -817,7 +816,7 @@ bool CPDF_SyntaxParser::BackwardsSearchToWord(const CFX_ByteStringC& tag,
   }
 }
 
-FX_FILESIZE CPDF_SyntaxParser::FindTag(const CFX_ByteStringC& tag,
+FX_FILESIZE CPDF_SyntaxParser::FindTag(const ByteStringView& tag,
                                        FX_FILESIZE limit) {
   int32_t taglen = tag.GetLength();
   int32_t match = 0;
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.h b/core/fpdfapi/parser/cpdf_syntax_parser.h
index 179058edf8..4e28c2fb92 100644
--- a/core/fpdfapi/parser/cpdf_syntax_parser.h
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.h
@@ -26,7 +26,7 @@ class CPDF_SyntaxParser {
   enum class ParseType { kStrict, kLoose };
 
   CPDF_SyntaxParser();
-  explicit CPDF_SyntaxParser(const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
+  explicit CPDF_SyntaxParser(const CFX_WeakPtr<ByteStringPool>& pPool);
   ~CPDF_SyntaxParser();
 
   void InitParser(const CFX_RetainPtr<IFX_SeekableReadStream>& pFileAccess,
@@ -56,16 +56,16 @@ class CPDF_SyntaxParser {
       bool bDecrypt,
       ParseType parse_type);
 
-  CFX_ByteString GetKeyword();
+  ByteString GetKeyword();
   void ToNextLine();
   void ToNextWord();
-  bool BackwardsSearchToWord(const CFX_ByteStringC& word, FX_FILESIZE limit);
-  FX_FILESIZE FindTag(const CFX_ByteStringC& tag, FX_FILESIZE limit);
+  bool BackwardsSearchToWord(const ByteStringView& word, FX_FILESIZE limit);
+  FX_FILESIZE FindTag(const ByteStringView& tag, FX_FILESIZE limit);
   void SetEncrypt(const CFX_RetainPtr<CPDF_CryptoHandler>& pCryptoHandler);
   bool ReadBlock(uint8_t* pBuf, uint32_t size);
   bool GetCharAt(FX_FILESIZE pos, uint8_t& ch);
-  CFX_ByteString GetNextWord(bool* bIsNumber);
-  CFX_ByteString PeekNextWord(bool* bIsNumber);
+  ByteString GetNextWord(bool* bIsNumber);
+  ByteString PeekNextWord(bool* bIsNumber);
 
   CFX_RetainPtr<IFX_SeekableReadStream> GetFileAccess() const;
 
@@ -88,11 +88,11 @@ class CPDF_SyntaxParser {
   void GetNextWordInternal(bool* bIsNumber);
   bool IsWholeWord(FX_FILESIZE startpos,
                    FX_FILESIZE limit,
-                   const CFX_ByteStringC& tag,
+                   const ByteStringView& tag,
                    bool checkKeyword);
 
-  CFX_ByteString ReadString();
-  CFX_ByteString ReadHexString();
+  ByteString ReadString();
+  ByteString ReadHexString();
   unsigned int ReadEOLMarkers(FX_FILESIZE pos);
   std::unique_ptr<CPDF_Stream> ReadStream(
       std::unique_ptr<CPDF_Dictionary> pDict,
@@ -122,7 +122,7 @@ class CPDF_SyntaxParser {
   CFX_RetainPtr<CPDF_CryptoHandler> m_pCryptoHandler;
   uint8_t m_WordBuffer[257];
   uint32_t m_WordSize;
-  CFX_WeakPtr<CFX_ByteStringPool> m_pPool;
+  CFX_WeakPtr<ByteStringPool> m_pPool;
 };
 
 #endif  // CORE_FPDFAPI_PARSER_CPDF_SYNTAX_PARSER_H_
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.cpp b/core/fpdfapi/parser/fpdf_parser_decode.cpp
index 77024f2f09..0180aaf749 100644
--- a/core/fpdfapi/parser/fpdf_parser_decode.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_decode.cpp
@@ -328,7 +328,7 @@ bool PDF_DataDecode(const uint8_t* src_buf,
                     bool bImageAcc,
                     uint8_t** dest_buf,
                     uint32_t* dest_size,
-                    CFX_ByteString* ImageEncoding,
+                    ByteString* ImageEncoding,
                     CPDF_Dictionary** pImageParms) {
   CPDF_Object* pDecoder = pDict ? pDict->GetDirectObjectFor("Filter") : nullptr;
   if (!pDecoder || (!pDecoder->IsArray() && !pDecoder->IsName()))
@@ -337,7 +337,7 @@ bool PDF_DataDecode(const uint8_t* src_buf,
   CPDF_Object* pParams =
       pDict ? pDict->GetDirectObjectFor("DecodeParms") : nullptr;
 
-  std::vector<std::pair<CFX_ByteString, CPDF_Object*>> DecoderArray;
+  std::vector<std::pair<ByteString, CPDF_Object*>> DecoderArray;
   if (CPDF_Array* pDecoders = pDecoder->AsArray()) {
     CPDF_Array* pParamsArray = ToArray(pParams);
     for (size_t i = 0; i < pDecoders->GetCount(); ++i) {
@@ -354,7 +354,7 @@ bool PDF_DataDecode(const uint8_t* src_buf,
   int nSize = pdfium::CollectionSize<int>(DecoderArray);
   for (int i = 0; i < nSize; ++i) {
     int estimated_size = i == nSize - 1 ? last_estimated_size : 0;
-    CFX_ByteString decoder = DecoderArray[i].first;
+    ByteString decoder = DecoderArray[i].first;
     CPDF_Dictionary* pParam = ToDictionary(DecoderArray[i].second);
     uint8_t* new_buf = nullptr;
     uint32_t new_size = 0xFFFFFFFF;
@@ -415,8 +415,8 @@ bool PDF_DataDecode(const uint8_t* src_buf,
   return true;
 }
 
-CFX_WideString PDF_DecodeText(const uint8_t* src_data, uint32_t src_len) {
-  CFX_WideString result;
+WideString PDF_DecodeText(const uint8_t* src_data, uint32_t src_len) {
+  WideString result;
   if (src_len >= 2 && ((src_data[0] == 0xfe && src_data[1] == 0xff) ||
                        (src_data[0] == 0xff && src_data[1] == 0xfe))) {
     bool bBE = src_data[0] == 0xfe;
@@ -455,16 +455,16 @@ CFX_WideString PDF_DecodeText(const uint8_t* src_data, uint32_t src_len) {
   return result;
 }
 
-CFX_WideString PDF_DecodeText(const CFX_ByteString& bstr) {
+WideString PDF_DecodeText(const ByteString& bstr) {
   return PDF_DecodeText(reinterpret_cast<const uint8_t*>(bstr.c_str()),
                         bstr.GetLength());
 }
 
-CFX_ByteString PDF_EncodeText(const wchar_t* pString, int len) {
+ByteString PDF_EncodeText(const wchar_t* pString, int len) {
   if (len == -1)
     len = FXSYS_wcslen(pString);
 
-  CFX_ByteString result;
+  ByteString result;
   char* dest_buf1 = result.GetBuffer(len);
   int i;
   for (i = 0; i < len; ++i) {
@@ -502,11 +502,11 @@ CFX_ByteString PDF_EncodeText(const wchar_t* pString, int len) {
   return result;
 }
 
-CFX_ByteString PDF_EncodeText(const CFX_WideString& str) {
+ByteString PDF_EncodeText(const WideString& str) {
   return PDF_EncodeText(str.c_str(), str.GetLength());
 }
 
-CFX_ByteString PDF_EncodeString(const CFX_ByteString& src, bool bHex) {
+ByteString PDF_EncodeString(const ByteString& src, bool bHex) {
   std::ostringstream result;
   int srclen = src.GetLength();
   if (bHex) {
@@ -518,7 +518,7 @@ CFX_ByteString PDF_EncodeString(const CFX_ByteString& src, bool bHex) {
       result << buf[1];
     }
     result << '>';
-    return CFX_ByteString(result);
+    return ByteString(result);
   }
   result << '(';
   for (int i = 0; i < srclen; ++i) {
@@ -536,7 +536,7 @@ CFX_ByteString PDF_EncodeString(const CFX_ByteString& src, bool bHex) {
     result << static_cast<char>(ch);
   }
   result << ')';
-  return CFX_ByteString(result);
+  return ByteString(result);
 }
 
 bool FlateEncode(const uint8_t* src_buf,
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.h b/core/fpdfapi/parser/fpdf_parser_decode.h
index 23ca0a0fae..6650b68c06 100644
--- a/core/fpdfapi/parser/fpdf_parser_decode.h
+++ b/core/fpdfapi/parser/fpdf_parser_decode.h
@@ -17,14 +17,14 @@ class CPDF_Dictionary;
 // Indexed by 8-bit char code, contains unicode code points.
 extern const uint16_t PDFDocEncoding[256];
 
-CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& orig);
-CFX_ByteString PDF_NameDecode(const CFX_ByteString& orig);
-CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig);
-CFX_ByteString PDF_EncodeString(const CFX_ByteString& src, bool bHex);
-CFX_WideString PDF_DecodeText(const uint8_t* pData, uint32_t size);
-CFX_WideString PDF_DecodeText(const CFX_ByteString& bstr);
-CFX_ByteString PDF_EncodeText(const wchar_t* pString, int len);
-CFX_ByteString PDF_EncodeText(const CFX_WideString& str);
+ByteString PDF_NameDecode(const ByteStringView& orig);
+ByteString PDF_NameDecode(const ByteString& orig);
+ByteString PDF_NameEncode(const ByteString& orig);
+ByteString PDF_EncodeString(const ByteString& src, bool bHex);
+WideString PDF_DecodeText(const uint8_t* pData, uint32_t size);
+WideString PDF_DecodeText(const ByteString& bstr);
+ByteString PDF_EncodeText(const wchar_t* pString, int len);
+ByteString PDF_EncodeText(const WideString& str);
 
 bool FlateEncode(const uint8_t* src_buf,
                  uint32_t src_size,
@@ -90,7 +90,7 @@ bool PDF_DataDecode(const uint8_t* src_buf,
                     bool bImageAcc,
                     uint8_t** dest_buf,
                     uint32_t* dest_size,
-                    CFX_ByteString* ImageEncoding,
+                    ByteString* ImageEncoding,
                     CPDF_Dictionary** pImageParms);
 
 #endif  // CORE_FPDFAPI_PARSER_FPDF_PARSER_DECODE_H_
diff --git a/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp b/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp
index c8e0c7a0e1..ae30959013 100644
--- a/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp
@@ -99,7 +99,7 @@ TEST(fpdf_parser_decode, EncodeText) {
 
   for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
     const auto& test_case = test_data[i];
-    CFX_ByteString output = PDF_EncodeText(test_case.input);
+    ByteString output = PDF_EncodeText(test_case.input);
     ASSERT_EQ(test_case.expected_length, output.GetLength()) << "for case "
                                                              << i;
     const char* str_ptr = output.c_str();
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index c6487f55a0..82804528ab 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -84,17 +84,17 @@ int32_t GetHeaderOffset(const CFX_RetainPtr<IFX_SeekableReadStream>& pFile) {
   return kInvalidHeaderOffset;
 }
 
-int32_t GetDirectInteger(CPDF_Dictionary* pDict, const CFX_ByteString& key) {
+int32_t GetDirectInteger(CPDF_Dictionary* pDict, const ByteString& key) {
   CPDF_Number* pObj = ToNumber(pDict->GetObjectFor(key));
   return pObj ? pObj->GetInteger() : 0;
 }
 
-CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& bstr) {
+ByteString PDF_NameDecode(const ByteStringView& bstr) {
   if (!bstr.Contains('#'))
-    return CFX_ByteString(bstr);
+    return ByteString(bstr);
 
   int size = bstr.GetLength();
-  CFX_ByteString result;
+  ByteString result;
   char* pDestStart = result.GetBuffer(size);
   char* pDest = pDestStart;
   for (int i = 0; i < size; i++) {
@@ -110,11 +110,11 @@ CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& bstr) {
   return result;
 }
 
-CFX_ByteString PDF_NameDecode(const CFX_ByteString& orig) {
-  return orig.Contains("#") ? PDF_NameDecode(orig.AsStringC()) : orig;
+ByteString PDF_NameDecode(const ByteString& orig) {
+  return orig.Contains("#") ? PDF_NameDecode(orig.AsStringView()) : orig;
 }
 
-CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
+ByteString PDF_NameEncode(const ByteString& orig) {
   uint8_t* src_buf = (uint8_t*)orig.c_str();
   int src_len = orig.GetLength();
   int dest_len = 0;
@@ -131,7 +131,7 @@ CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
   if (dest_len == src_len)
     return orig;
 
-  CFX_ByteString res;
+  ByteString res;
   char* dest_buf = res.GetBuffer(dest_len);
   dest_len = 0;
   for (i = 0; i < src_len; i++) {
@@ -167,7 +167,7 @@ std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj) {
       buf << PDF_EncodeString(pObj->GetString(), pObj->AsString()->IsHex());
       break;
     case CPDF_Object::NAME: {
-      CFX_ByteString str = pObj->GetString();
+      ByteString str = pObj->GetString();
       buf << "/" << PDF_NameEncode(str);
       break;
     }
@@ -193,7 +193,7 @@ std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj) {
       const CPDF_Dictionary* p = pObj->AsDictionary();
       buf << "<<";
       for (const auto& it : *p) {
-        const CFX_ByteString& key = it.first;
+        const ByteString& key = it.first;
         CPDF_Object* pValue = it.second.get();
         buf << "/" << PDF_NameEncode(key);
         if (pValue && !pValue->IsInline()) {
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.h b/core/fpdfapi/parser/fpdf_parser_utility.h
index 94ee1fcfd3..5f85551a53 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.h
+++ b/core/fpdfapi/parser/fpdf_parser_utility.h
@@ -41,7 +41,7 @@ constexpr int32_t kInvalidHeaderOffset = -1;
 // |kInvalidHeaderOffset|.
 int32_t GetHeaderOffset(const CFX_RetainPtr<IFX_SeekableReadStream>& pFile);
 
-int32_t GetDirectInteger(CPDF_Dictionary* pDict, const CFX_ByteString& key);
+int32_t GetDirectInteger(CPDF_Dictionary* pDict, const ByteString& key);
 
 std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj);