diff --git a/core/fpdfdoc/cpdf_filespec.cpp b/core/fpdfdoc/cpdf_filespec.cpp
index 7fe8ec8..59915ea 100644
--- a/core/fpdfdoc/cpdf_filespec.cpp
+++ b/core/fpdfdoc/cpdf_filespec.cpp
@@ -50,7 +50,7 @@
 
 }  // namespace
 
-CFX_WideString CPDF_FileSpec::DecodeFileName(const CFX_WideStringC& filepath) {
+CFX_WideString CPDF_FileSpec::DecodeFileName(const CFX_WideString& filepath) {
   if (filepath.GetLength() <= 1)
     return CFX_WideString();
 
@@ -108,7 +108,7 @@
   } else {
     return false;
   }
-  *csFileName = DecodeFileName(csFileName->AsStringC());
+  *csFileName = DecodeFileName(*csFileName);
   return true;
 }
 
@@ -116,7 +116,7 @@
 
 CPDF_FileSpec::~CPDF_FileSpec() {}
 
-CFX_WideString CPDF_FileSpec::EncodeFileName(const CFX_WideStringC& filepath) {
+CFX_WideString CPDF_FileSpec::EncodeFileName(const CFX_WideString& filepath) {
   if (filepath.GetLength() <= 1)
     return CFX_WideString();
 
@@ -145,7 +145,7 @@
 #endif
 }
 
-void CPDF_FileSpec::SetFileName(const CFX_WideStringC& wsFileName) {
+void CPDF_FileSpec::SetFileName(const CFX_WideString& wsFileName) {
   if (!m_pObj)
     return;
 
diff --git a/core/fpdfdoc/cpdf_filespec.h b/core/fpdfdoc/cpdf_filespec.h
index fb71b57..04baf2e 100644
--- a/core/fpdfdoc/cpdf_filespec.h
+++ b/core/fpdfdoc/cpdf_filespec.h
@@ -20,16 +20,16 @@
   ~CPDF_FileSpec();
 
   // Convert a platform dependent file name into pdf format.
-  static CFX_WideString EncodeFileName(const CFX_WideStringC& filepath);
+  static CFX_WideString EncodeFileName(const CFX_WideString& filepath);
 
   // Convert a pdf file name into platform dependent format.
-  static CFX_WideString DecodeFileName(const CFX_WideStringC& filepath);
+  static CFX_WideString DecodeFileName(const CFX_WideString& filepath);
 
   CPDF_Object* GetObj() const { return m_pObj.Get(); }
   bool GetFileName(CFX_WideString* wsFileName) const;
 
   // Set this file spec to refer to a file name (not a url).
-  void SetFileName(const CFX_WideStringC& wsFileName);
+  void SetFileName(const CFX_WideString& wsFileName);
 
  private:
   CFX_UnownedPtr<CPDF_Object> const m_pObj;
diff --git a/core/fpdfdoc/cpdf_interform.cpp b/core/fpdfdoc/cpdf_interform.cpp
index 766ec6c..88787d2 100644
--- a/core/fpdfdoc/cpdf_interform.cpp
+++ b/core/fpdfdoc/cpdf_interform.cpp
@@ -1179,7 +1179,7 @@
 }
 
 std::unique_ptr<CFDF_Document> CPDF_InterForm::ExportToFDF(
-    const CFX_WideStringC& pdf_path,
+    const CFX_WideString& pdf_path,
     bool bSimpleFileSpec) const {
   std::vector<CPDF_FormField*> fields;
   size_t nCount = m_pFieldTree->m_Root.CountFields();
@@ -1189,7 +1189,7 @@
 }
 
 std::unique_ptr<CFDF_Document> CPDF_InterForm::ExportToFDF(
-    const CFX_WideStringC& pdf_path,
+    const CFX_WideString& pdf_path,
     const std::vector<CPDF_FormField*>& fields,
     bool bIncludeOrExclude,
     bool bSimpleFileSpec) const {
diff --git a/core/fpdfdoc/cpdf_interform.h b/core/fpdfdoc/cpdf_interform.h
index 5399392..23530e5 100644
--- a/core/fpdfdoc/cpdf_interform.h
+++ b/core/fpdfdoc/cpdf_interform.h
@@ -71,11 +71,11 @@
   bool CheckRequiredFields(const std::vector<CPDF_FormField*>* fields,
                            bool bIncludeOrExclude) const;
 
-  std::unique_ptr<CFDF_Document> ExportToFDF(const CFX_WideStringC& pdf_path,
+  std::unique_ptr<CFDF_Document> ExportToFDF(const CFX_WideString& pdf_path,
                                              bool bSimpleFileSpec) const;
 
   std::unique_ptr<CFDF_Document> ExportToFDF(
-      const CFX_WideStringC& pdf_path,
+      const CFX_WideString& pdf_path,
       const std::vector<CPDF_FormField*>& fields,
       bool bIncludeOrExclude,
       bool bSimpleFileSpec) const;
diff --git a/core/fxcrt/cfx_string_c_template.h b/core/fxcrt/cfx_string_c_template.h
index 75c2be0..3a0ad74 100644
--- a/core/fxcrt/cfx_string_c_template.h
+++ b/core/fxcrt/cfx_string_c_template.h
@@ -11,6 +11,7 @@
 #include <type_traits>
 #include <vector>
 
+#include "core/fxcrt/cfx_unowned_ptr.h"
 #include "core/fxcrt/fx_system.h"
 #include "third_party/base/stl_util.h"
 
@@ -75,22 +76,23 @@
   }
 
   const_iterator begin() const {
-    return reinterpret_cast<const CharType*>(m_Ptr);
+    return reinterpret_cast<const CharType*>(m_Ptr.Get());
   }
   const_iterator end() const {
-    return m_Ptr ? reinterpret_cast<const CharType*>(m_Ptr) + m_Length
+    return m_Ptr ? reinterpret_cast<const CharType*>(m_Ptr.Get()) + m_Length
                  : nullptr;
   }
 
   bool operator==(const CharType* ptr) const {
     return FXSYS_len(ptr) == m_Length &&
-           FXSYS_cmp(ptr, reinterpret_cast<const CharType*>(m_Ptr), m_Length) ==
-               0;
+           FXSYS_cmp(ptr, reinterpret_cast<const CharType*>(m_Ptr.Get()),
+                     m_Length) == 0;
   }
   bool operator==(const CFX_StringCTemplate& other) const {
     return other.m_Length == m_Length &&
-           FXSYS_cmp(reinterpret_cast<const CharType*>(other.m_Ptr),
-                     reinterpret_cast<const CharType*>(m_Ptr), m_Length) == 0;
+           FXSYS_cmp(reinterpret_cast<const CharType*>(other.m_Ptr.Get()),
+                     reinterpret_cast<const CharType*>(m_Ptr.Get()),
+                     m_Length) == 0;
   }
   bool operator!=(const CharType* ptr) const { return !(*this == ptr); }
   bool operator!=(const CFX_StringCTemplate& other) const {
@@ -104,28 +106,28 @@
     uint32_t strid = 0;
     FX_STRSIZE size = std::min(4, m_Length - start_pos);
     for (FX_STRSIZE i = 0; i < size; i++)
-      strid = strid * 256 + m_Ptr[start_pos + i];
+      strid = strid * 256 + m_Ptr.Get()[start_pos + i];
 
     return strid << ((4 - size) * 8);
   }
 
-  const UnsignedType* raw_str() const { return m_Ptr; }
+  const UnsignedType* raw_str() const { return m_Ptr.Get(); }
   const CharType* c_str() const {
-    return reinterpret_cast<const CharType*>(m_Ptr);
+    return reinterpret_cast<const CharType*>(m_Ptr.Get());
   }
 
   FX_STRSIZE GetLength() const { return m_Length; }
   bool IsEmpty() const { return m_Length == 0; }
 
-  UnsignedType GetAt(FX_STRSIZE index) const { return m_Ptr[index]; }
+  UnsignedType GetAt(FX_STRSIZE index) const { return m_Ptr.Get()[index]; }
   CharType CharAt(FX_STRSIZE index) const {
-    return static_cast<CharType>(m_Ptr[index]);
+    return static_cast<CharType>(m_Ptr.Get()[index]);
   }
 
   FX_STRSIZE Find(CharType ch) const {
-    const UnsignedType* found = reinterpret_cast<const UnsignedType*>(
-        FXSYS_chr(reinterpret_cast<const CharType*>(m_Ptr), ch, m_Length));
-    return found ? found - m_Ptr : -1;
+    const UnsignedType* found = reinterpret_cast<const UnsignedType*>(FXSYS_chr(
+        reinterpret_cast<const CharType*>(m_Ptr.Get()), ch, m_Length));
+    return found ? found - m_Ptr.Get() : -1;
   }
 
   CFX_StringCTemplate Mid(FX_STRSIZE index, FX_STRSIZE count = -1) const {
@@ -136,14 +138,14 @@
     if (count < 0 || count > m_Length - index)
       count = m_Length - index;
 
-    return CFX_StringCTemplate(m_Ptr + index, count);
+    return CFX_StringCTemplate(m_Ptr.Get() + index, count);
   }
 
   CFX_StringCTemplate Left(FX_STRSIZE count) const {
     if (count <= 0)
       return CFX_StringCTemplate();
 
-    return CFX_StringCTemplate(m_Ptr, std::min(count, m_Length));
+    return CFX_StringCTemplate(m_Ptr.Get(), std::min(count, m_Length));
   }
 
   CFX_StringCTemplate Right(FX_STRSIZE count) const {
@@ -151,20 +153,22 @@
       return CFX_StringCTemplate();
 
     count = std::min(count, m_Length);
-    return CFX_StringCTemplate(m_Ptr + m_Length - count, count);
+    return CFX_StringCTemplate(m_Ptr.Get() + m_Length - count, count);
   }
 
-  const UnsignedType& operator[](size_t index) const { return m_Ptr[index]; }
+  const UnsignedType& operator[](size_t index) const {
+    return m_Ptr.Get()[index];
+  }
 
   bool operator<(const CFX_StringCTemplate& that) const {
-    int result = FXSYS_cmp(reinterpret_cast<const CharType*>(m_Ptr),
-                           reinterpret_cast<const CharType*>(that.m_Ptr),
+    int result = FXSYS_cmp(reinterpret_cast<const CharType*>(m_Ptr.Get()),
+                           reinterpret_cast<const CharType*>(that.m_Ptr.Get()),
                            std::min(m_Length, that.m_Length));
     return result < 0 || (result == 0 && m_Length < that.m_Length);
   }
 
  protected:
-  const UnsignedType* m_Ptr;
+  CFX_UnownedPtr<const UnsignedType> m_Ptr;
   FX_STRSIZE m_Length;
 
  private:
diff --git a/core/fxcrt/cfx_unowned_ptr.h b/core/fxcrt/cfx_unowned_ptr.h
index bc58144..d91833a 100644
--- a/core/fxcrt/cfx_unowned_ptr.h
+++ b/core/fxcrt/cfx_unowned_ptr.h
@@ -64,7 +64,7 @@
 #if defined(MEMORY_TOOL_REPLACES_ALLOCATOR)
   void Probe() {
     if (m_pObj)
-      reinterpret_cast<volatile uint8_t*>(m_pObj)[0];
+      reinterpret_cast<const volatile uint8_t*>(m_pObj)[0];
   }
 #endif
 
diff --git a/fpdfsdk/cpdfsdk_interform.cpp b/fpdfsdk/cpdfsdk_interform.cpp
index 2d02a7a..76cb6fd 100644
--- a/fpdfsdk/cpdfsdk_interform.cpp
+++ b/fpdfsdk/cpdfsdk_interform.cpp
@@ -502,9 +502,8 @@
     const std::vector<CPDF_FormField*>& fields,
     bool bIncludeOrExclude,
     CFX_ByteTextBuf& textBuf) {
-  std::unique_ptr<CFDF_Document> pFDF =
-      m_pInterForm->ExportToFDF(m_pFormFillEnv->JS_docGetFilePath().AsStringC(),
-                                fields, bIncludeOrExclude, false);
+  std::unique_ptr<CFDF_Document> pFDF = m_pInterForm->ExportToFDF(
+      m_pFormFillEnv->JS_docGetFilePath(), fields, bIncludeOrExclude, false);
   return pFDF ? pFDF->WriteBuf(textBuf) : false;
 }
 
@@ -521,8 +520,8 @@
   if (!m_pFormFillEnv || !m_pInterForm)
     return false;
 
-  std::unique_ptr<CFDF_Document> pFDFDoc = m_pInterForm->ExportToFDF(
-      m_pFormFillEnv->JS_docGetFilePath().AsStringC(), false);
+  std::unique_ptr<CFDF_Document> pFDFDoc =
+      m_pInterForm->ExportToFDF(m_pFormFillEnv->JS_docGetFilePath(), false);
   if (!pFDFDoc)
     return false;
 
@@ -543,8 +542,8 @@
 }
 
 bool CPDFSDK_InterForm::ExportFormToFDFTextBuf(CFX_ByteTextBuf& textBuf) {
-  std::unique_ptr<CFDF_Document> pFDF = m_pInterForm->ExportToFDF(
-      m_pFormFillEnv->JS_docGetFilePath().AsStringC(), false);
+  std::unique_ptr<CFDF_Document> pFDF =
+      m_pInterForm->ExportToFDF(m_pFormFillEnv->JS_docGetFilePath(), false);
   return pFDF && pFDF->WriteBuf(textBuf);
 }
 
diff --git a/xfa/fxfa/fm2js/cxfa_fmlexer.cpp b/xfa/fxfa/fm2js/cxfa_fmlexer.cpp
index db7cc95..433839a 100644
--- a/xfa/fxfa/fm2js/cxfa_fmlexer.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmlexer.cpp
@@ -94,6 +94,8 @@
 CXFA_FMToken::CXFA_FMToken(uint32_t uLineNum)
     : m_type(TOKreserver), m_uLinenum(uLineNum) {}
 
+CXFA_FMToken::~CXFA_FMToken() {}
+
 CXFA_FMLexer::CXFA_FMLexer(const CFX_WideStringC& wsFormCalc)
     : m_ptr(wsFormCalc.c_str()),
       m_end(m_ptr + wsFormCalc.GetLength() - 1),
diff --git a/xfa/fxfa/fm2js/cxfa_fmlexer.h b/xfa/fxfa/fm2js/cxfa_fmlexer.h
index f4f8a68..3b5b372 100644
--- a/xfa/fxfa/fm2js/cxfa_fmlexer.h
+++ b/xfa/fxfa/fm2js/cxfa_fmlexer.h
@@ -95,6 +95,7 @@
  public:
   CXFA_FMToken();
   explicit CXFA_FMToken(uint32_t uLineNum);
+  ~CXFA_FMToken();
 
   CFX_WideStringC m_wstring;
   XFA_FM_TOKEN m_type;