4 files changed, 11 insertions, 7 deletions
diff --git a/core/fpdfapi/parser/cfdf_document.cpp b/core/fpdfapi/parser/cfdf_document.cpp
index 85e2f6ef04..b00806967b 100644
--- a/core/fpdfapi/parser/cfdf_document.cpp
+++ b/core/fpdfapi/parser/cfdf_document.cpp
@@ -7,6 +7,7 @@
 #include "core/fpdfapi/parser/cfdf_document.h"
 
 #include <memory>
+#include <sstream>
 #include <utility>
 
 #include "core/fpdfapi/edit/cpdf_creator.h"
@@ -88,10 +89,11 @@ void CFDF_Document::ParseStream(
   }
 }
 
-bool CFDF_Document::WriteBuf(CFX_ByteTextBuf& buf) const {
+CFX_ByteString CFDF_Document::WriteToString() const {
   if (!m_pRootDict)
-    return false;
+    return CFX_ByteString();
 
+  std::ostringstream buf;
   buf << "%FDF-1.2\r\n";
   for (const auto& pair : *this)
     buf << pair.first << " 0 obj\r\n"
@@ -99,5 +101,6 @@ bool CFDF_Document::WriteBuf(CFX_ByteTextBuf& buf) const {
 
   buf << "trailer\r\n<</Root " << m_pRootDict->GetObjNum()
       << " 0 R>>\r\n%%EOF\r\n";
-  return true;
+
+  return CFX_ByteString(buf);
 }
diff --git a/core/fpdfapi/parser/cfdf_document.h b/core/fpdfapi/parser/cfdf_document.h
index 9a13877544..45bf83d426 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;
 
-  bool WriteBuf(CFX_ByteTextBuf& buf) const;
+  CFX_ByteString WriteToString() const;
   CPDF_Dictionary* GetRoot() const { return m_pRootDict.Get(); }
 
  protected:
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index 0c0ca6644f..7cea16569f 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -151,7 +151,7 @@ CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
   return res;
 }
 
-CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj) {
+std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj) {
   if (!pObj) {
     buf << " null";
     return buf;
@@ -211,7 +211,8 @@ CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj) {
       buf << p->GetDict() << "stream\r\n";
       auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(p);
       pAcc->LoadAllData(true);
-      buf.AppendBlock(pAcc->GetData(), pAcc->GetSize());
+      buf.write(reinterpret_cast<const char*>(pAcc->GetData()),
+                pAcc->GetSize());
       buf << "\r\nendstream";
       break;
     }
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.h b/core/fpdfapi/parser/fpdf_parser_utility.h
index 5e764ad07b..47431e47dd 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.h
+++ b/core/fpdfapi/parser/fpdf_parser_utility.h
@@ -43,6 +43,6 @@ int32_t GetHeaderOffset(const CFX_RetainPtr<IFX_SeekableReadStream>& pFile);
 
 int32_t GetDirectInteger(CPDF_Dictionary* pDict, const CFX_ByteString& key);
 
-CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj);
+std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj);
 
 #endif  // CORE_FPDFAPI_PARSER_FPDF_PARSER_UTILITY_H_