Rename IFGAS_Stream to CFGAS_Stream

This CL replaces IFGAS_Stream with the only implementation CFGAS_Stream.
The CreateReadStream and CreateWriteStream methods are removed in favour
of calling MakeRetain directly.

Change-Id: I882a89258f642e24fc3d631587db05652bd53ded
Reviewed-on: https://pdfium-review.googlesource.com/4210
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

29 files changed, 162 insertions, 260 deletions

diff --git a/BUILD.gn b/BUILD.gn
index ff9a4a4d44..4b42ac7d76 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1427,10 +1427,10 @@ if (pdf_enable_xfa) {
       "xfa/fde/xml/cfde_xmltext.h",
       "xfa/fgas/crt/cfgas_formatstring.cpp",
       "xfa/fgas/crt/cfgas_formatstring.h",
+      "xfa/fgas/crt/cfgas_stream.cpp",
+      "xfa/fgas/crt/cfgas_stream.h",
       "xfa/fgas/crt/fgas_codepage.h",
       "xfa/fgas/crt/fgas_language.h",
-      "xfa/fgas/crt/ifgas_stream.cpp",
-      "xfa/fgas/crt/ifgas_stream.h",
       "xfa/fgas/font/cfgas_fontmgr.cpp",
       "xfa/fgas/font/cfgas_fontmgr.h",
       "xfa/fgas/font/cfgas_gefont.cpp",
diff --git a/testing/libfuzzer/pdf_cfx_saxreader_fuzzer.cc b/testing/libfuzzer/pdf_cfx_saxreader_fuzzer.cc
index 31e24e82f2..c27273f29b 100644
--- a/testing/libfuzzer/pdf_cfx_saxreader_fuzzer.cc
+++ b/testing/libfuzzer/pdf_cfx_saxreader_fuzzer.cc
@@ -6,7 +6,7 @@
 
 #include "core/fxcrt/cfx_retain_ptr.h"
 #include "core/fxcrt/xml/cfx_saxreader.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   CFX_SAXReader reader;
diff --git a/testing/libfuzzer/pdf_css_fuzzer.cc b/testing/libfuzzer/pdf_css_fuzzer.cc
index 9f5cdfec45..fef3de74b7 100644
--- a/testing/libfuzzer/pdf_css_fuzzer.cc
+++ b/testing/libfuzzer/pdf_css_fuzzer.cc
@@ -8,7 +8,7 @@
 #include "core/fxcrt/fx_string.h"
 #include "xfa/fde/css/cfde_csssyntaxparser.h"
 #include "xfa/fde/css/fde_css.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   CFX_WideString input = CFX_WideString::FromUTF8(
diff --git a/testing/libfuzzer/pdf_xml_fuzzer.cc b/testing/libfuzzer/pdf_xml_fuzzer.cc
index 1f368699f4..3806f59781 100644
--- a/testing/libfuzzer/pdf_xml_fuzzer.cc
+++ b/testing/libfuzzer/pdf_xml_fuzzer.cc
@@ -13,7 +13,7 @@
 #include "xfa/fde/xml/cfde_xmldoc.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmlparser.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 namespace {
 
@@ -51,11 +51,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   if (!safe_size.IsValid())
     return 0;
 
-  CFX_RetainPtr<IFGAS_Stream> stream = IFGAS_Stream::CreateReadStream(
-      IFX_MemoryStream::Create(const_cast<uint8_t*>(data), size));
-  if (!stream)
-    return 0;
-
+  CFX_RetainPtr<CFGAS_Stream> stream =
+      pdfium::MakeRetain<CFGAS_Stream>(const_cast<uint8_t*>(data), size);
   auto doc = pdfium::MakeUnique<CFDE_XMLDoc>();
   if (!doc->LoadXML(pdfium::MakeUnique<CFDE_XMLParser>(doc->GetRoot(), stream)))
     return 0;
diff --git a/xfa/fde/cfde_txtedtengine.cpp b/xfa/fde/cfde_txtedtengine.cpp
index 84aafed433..136735c16e 100644
--- a/xfa/fde/cfde_txtedtengine.cpp
+++ b/xfa/fde/cfde_txtedtengine.cpp
@@ -106,7 +106,7 @@ CFDE_TxtEdtPage* CFDE_TxtEdtEngine::GetPage(int32_t nIndex) {
 }
 
 void CFDE_TxtEdtEngine::SetTextByStream(
-    const CFX_RetainPtr<IFGAS_Stream>& pStream) {
+    const CFX_RetainPtr<CFGAS_Stream>& pStream) {
   ResetEngine();
   int32_t nIndex = 0;
   if (pStream && pStream->GetLength()) {
@@ -118,7 +118,7 @@ void CFDE_TxtEdtEngine::SetTextByStream(
     bool bPreIsCR = false;
     if (bValid) {
       int32_t nPos = pStream->GetBOMLength();
-      pStream->Seek(FX_STREAMSEEK_Begin, nPos);
+      pStream->Seek(CFGAS_Stream::Pos::Begin, nPos);
       int32_t nPlateSize = std::min(nStreamLength, m_pTxtBuf->GetChunkSize());
       wchar_t* lpwstr = FX_Alloc(wchar_t, nPlateSize);
       bool bEos = false;
diff --git a/xfa/fde/cfde_txtedtengine.h b/xfa/fde/cfde_txtedtengine.h
index 020b8c93df..bbdef8fd7a 100644
--- a/xfa/fde/cfde_txtedtengine.h
+++ b/xfa/fde/cfde_txtedtengine.h
@@ -31,7 +31,7 @@ class CFDE_TxtEdtEngine {
   int32_t CountPages() const;
   CFDE_TxtEdtPage* GetPage(int32_t nIndex);
 
-  void SetTextByStream(const CFX_RetainPtr<IFGAS_Stream>& pStream);
+  void SetTextByStream(const CFX_RetainPtr<CFGAS_Stream>& pStream);
   void SetText(const CFX_WideString& wsText);
   int32_t GetTextLength() const;
   CFX_WideString GetText(int32_t nStart, int32_t nCount) const;
diff --git a/xfa/fde/css/cfde_csstextbuf.cpp b/xfa/fde/css/cfde_csstextbuf.cpp
index 149ed31e98..2d8f93f2b3 100644
--- a/xfa/fde/css/cfde_csstextbuf.cpp
+++ b/xfa/fde/css/cfde_csstextbuf.cpp
@@ -41,24 +41,6 @@ bool CFDE_CSSTextBuf::EstimateSize(int32_t iAllocSize) {
   return ExpandBuf(iAllocSize);
 }
 
-int32_t CFDE_CSSTextBuf::LoadFromStream(
-    const CFX_RetainPtr<IFGAS_Stream>& pTxtStream,
-    int32_t iStreamOffset,
-    int32_t iMaxChars,
-    bool& bEOS) {
-  ASSERT(iStreamOffset >= 0 && iMaxChars > 0);
-  Clear();
-  m_bExtBuf = false;
-  if (!ExpandBuf(iMaxChars))
-    return 0;
-
-  if (pTxtStream->GetPosition() != iStreamOffset)
-    pTxtStream->Seek(FX_STREAMSEEK_Begin, iStreamOffset);
-
-  m_iDatLen = pTxtStream->ReadString(m_pBuffer, iMaxChars, &bEOS);
-  return m_iDatLen;
-}
-
 bool CFDE_CSSTextBuf::ExpandBuf(int32_t iDesiredSize) {
   if (m_bExtBuf)
     return false;
diff --git a/xfa/fde/css/cfde_csstextbuf.h b/xfa/fde/css/cfde_csstextbuf.h
index 52c76210ce..43ff03aa07 100644
--- a/xfa/fde/css/cfde_csstextbuf.h
+++ b/xfa/fde/css/cfde_csstextbuf.h
@@ -10,7 +10,7 @@
 #include "core/fxcrt/cfx_retain_ptr.h"
 #include "core/fxcrt/fx_memory.h"
 #include "core/fxcrt/fx_system.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 class CFDE_CSSTextBuf {
  public:
@@ -19,10 +19,6 @@ class CFDE_CSSTextBuf {
 
   bool AttachBuffer(const wchar_t* pBuffer, int32_t iBufLen);
   bool EstimateSize(int32_t iAllocSize);
-  int32_t LoadFromStream(const CFX_RetainPtr<IFGAS_Stream>& pTxtStream,
-                         int32_t iStreamOffset,
-                         int32_t iMaxChars,
-                         bool& bEOS);
   bool AppendChar(wchar_t wch) {
     if (m_iDatLen >= m_iBufLen && !ExpandBuf(m_iBufLen * 2))
       return false;
diff --git a/xfa/fde/css/fde_css.h b/xfa/fde/css/fde_css.h
index ae4f36c93d..9e56fce59a 100644
--- a/xfa/fde/css/fde_css.h
+++ b/xfa/fde/css/fde_css.h
@@ -8,7 +8,7 @@
 #define XFA_FDE_CSS_FDE_CSS_H_
 
 #include "core/fxge/fx_dib.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 #include "xfa/fgas/font/cfgas_fontmgr.h"
 
 enum FDE_CSSVALUETYPE {
diff --git a/xfa/fde/xml/cfde_xmldoc.cpp b/xfa/fde/xml/cfde_xmldoc.cpp
index 209ce9c68f..256164c5f8 100644
--- a/xfa/fde/xml/cfde_xmldoc.cpp
+++ b/xfa/fde/xml/cfde_xmldoc.cpp
@@ -47,7 +47,7 @@ void CFDE_XMLDoc::CloseXML() {
   m_pXMLParser.reset();
 }
 
-void CFDE_XMLDoc::SaveXMLNode(const CFX_RetainPtr<IFGAS_Stream>& pXMLStream,
+void CFDE_XMLDoc::SaveXMLNode(const CFX_RetainPtr<CFGAS_Stream>& pXMLStream,
                               CFDE_XMLNode* pINode) {
   CFDE_XMLNode* pNode = (CFDE_XMLNode*)pINode;
   switch (pNode->GetType()) {
diff --git a/xfa/fde/xml/cfde_xmldoc.h b/xfa/fde/xml/cfde_xmldoc.h
index 6143750428..b84c9c00a0 100644
--- a/xfa/fde/xml/cfde_xmldoc.h
+++ b/xfa/fde/xml/cfde_xmldoc.h
@@ -12,7 +12,7 @@
 #include "core/fxcrt/cfx_retain_ptr.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmlparser.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 class CFDE_XMLDoc {
  public:
@@ -24,14 +24,14 @@ class CFDE_XMLDoc {
   void CloseXML();
 
   CFDE_XMLNode* GetRoot() const { return m_pRoot.get(); }
-  void SaveXMLNode(const CFX_RetainPtr<IFGAS_Stream>& pXMLStream,
+  void SaveXMLNode(const CFX_RetainPtr<CFGAS_Stream>& pXMLStream,
                    CFDE_XMLNode* pNode);
 
  private:
   int32_t m_iStatus;
   std::unique_ptr<CFDE_XMLNode> m_pRoot;
   std::unique_ptr<CFDE_XMLParser> m_pXMLParser;
-  CFX_RetainPtr<IFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFGAS_Stream> m_pStream;
 };
 
 #endif  // XFA_FDE_XML_CFDE_XMLDOC_H_
diff --git a/xfa/fde/xml/cfde_xmlnode.cpp b/xfa/fde/xml/cfde_xmlnode.cpp
index e4d7880cac..149d18c3d6 100644
--- a/xfa/fde/xml/cfde_xmlnode.cpp
+++ b/xfa/fde/xml/cfde_xmlnode.cpp
@@ -329,7 +329,7 @@ std::unique_ptr<CFDE_XMLNode> CFDE_XMLNode::Clone() {
   return nullptr;
 }
 
-void CFDE_XMLNode::SaveXMLNode(const CFX_RetainPtr<IFGAS_Stream>& pXMLStream) {
+void CFDE_XMLNode::SaveXMLNode(const CFX_RetainPtr<CFGAS_Stream>& pXMLStream) {
   CFDE_XMLNode* pNode = (CFDE_XMLNode*)this;
   switch (pNode->GetType()) {
     case FDE_XMLNODE_Instruction: {
diff --git a/xfa/fde/xml/cfde_xmlnode.h b/xfa/fde/xml/cfde_xmlnode.h
index 3cfcd5c980..a04bd8c812 100644
--- a/xfa/fde/xml/cfde_xmlnode.h
+++ b/xfa/fde/xml/cfde_xmlnode.h
@@ -10,7 +10,7 @@
 #include <memory>
 
 #include "core/fxcrt/cfx_retain_ptr.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 enum FDE_XMLNODETYPE {
   FDE_XMLNODE_Unknown = 0,
@@ -64,7 +64,7 @@ class CFDE_XMLNode {
   bool InsertNodeItem(CFDE_XMLNode::NodeItem eItem, CFDE_XMLNode* pNode);
   CFDE_XMLNode* RemoveNodeItem(CFDE_XMLNode::NodeItem eItem);
 
-  void SaveXMLNode(const CFX_RetainPtr<IFGAS_Stream>& pXMLStream);
+  void SaveXMLNode(const CFX_RetainPtr<CFGAS_Stream>& pXMLStream);
 
   CFDE_XMLNode* m_pParent;
   CFDE_XMLNode* m_pChild;
diff --git a/xfa/fde/xml/cfde_xmlparser.cpp b/xfa/fde/xml/cfde_xmlparser.cpp
index 5b8993de1b..c29dfc38ab 100644
--- a/xfa/fde/xml/cfde_xmlparser.cpp
+++ b/xfa/fde/xml/cfde_xmlparser.cpp
@@ -15,7 +15,7 @@
 #include "xfa/fde/xml/cfde_xmltext.h"
 
 CFDE_XMLParser::CFDE_XMLParser(CFDE_XMLNode* pParent,
-                               const CFX_RetainPtr<IFGAS_Stream>& pStream)
+                               const CFX_RetainPtr<CFGAS_Stream>& pStream)
     : m_nElementStart(0),
       m_dwCheckStatus(0),
       m_dwCurrentCheckStatus(0),
diff --git a/xfa/fde/xml/cfde_xmlparser.h b/xfa/fde/xml/cfde_xmlparser.h
index 42f590ce21..f1a7888fa7 100644
--- a/xfa/fde/xml/cfde_xmlparser.h
+++ b/xfa/fde/xml/cfde_xmlparser.h
@@ -16,13 +16,13 @@
 
 class CFDE_XMLElement;
 class CFDE_XMLNode;
-class IFGAS_Stream;
+class CFGAS_Stream;
 class IFX_Pause;
 
 class CFDE_XMLParser {
  public:
   CFDE_XMLParser(CFDE_XMLNode* pParent,
-                 const CFX_RetainPtr<IFGAS_Stream>& pStream);
+                 const CFX_RetainPtr<CFGAS_Stream>& pStream);
   ~CFDE_XMLParser();
 
   int32_t DoParser(IFX_Pause* pPause);
@@ -34,7 +34,7 @@ class CFDE_XMLParser {
   uint16_t m_dwCurrentCheckStatus;
 
  private:
-  CFX_RetainPtr<IFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFGAS_Stream> m_pStream;
   std::unique_ptr<CFDE_XMLSyntaxParser> m_pParser;
   CFDE_XMLNode* m_pParent;
   CFDE_XMLNode* m_pChild;
diff --git a/xfa/fde/xml/cfde_xmlsyntaxparser.cpp b/xfa/fde/xml/cfde_xmlsyntaxparser.cpp
index 78382058ec..10eefdc012 100644
--- a/xfa/fde/xml/cfde_xmlsyntaxparser.cpp
+++ b/xfa/fde/xml/cfde_xmlsyntaxparser.cpp
@@ -80,7 +80,7 @@ int32_t GetUTF8EncodeLength(const std::vector<wchar_t>& src,
 }  // namespace
 
 CFDE_XMLSyntaxParser::CFDE_XMLSyntaxParser(
-    const CFX_RetainPtr<IFGAS_Stream>& pStream)
+    const CFX_RetainPtr<CFGAS_Stream>& pStream)
     : m_pStream(pStream),
       m_iXMLPlaneSize(32 * 1024),
       m_iCurrentPos(0),
@@ -144,9 +144,9 @@ FDE_XmlSyntaxResult CFDE_XMLSyntaxParser::DoSyntaxParse() {
       }
       m_ParsedChars += m_End;
       m_iParsedBytes = m_iCurrentPos;
-      if (m_pStream->GetPosition() != m_iCurrentPos) {
-        m_pStream->Seek(FX_STREAMSEEK_Begin, m_iCurrentPos);
-      }
+      if (m_pStream->GetPosition() != m_iCurrentPos)
+        m_pStream->Seek(CFGAS_Stream::Pos::Begin, m_iCurrentPos);
+
       m_iBufferChars =
           m_pStream->ReadString(m_Buffer.data(), m_iXMLPlaneSize, &m_bEOS);
       iPos = m_pStream->GetPosition();
diff --git a/xfa/fde/xml/cfde_xmlsyntaxparser.h b/xfa/fde/xml/cfde_xmlsyntaxparser.h
index f229cc02b1..aa4e91827e 100644
--- a/xfa/fde/xml/cfde_xmlsyntaxparser.h
+++ b/xfa/fde/xml/cfde_xmlsyntaxparser.h
@@ -14,7 +14,7 @@
 #include "core/fxcrt/cfx_retain_ptr.h"
 #include "core/fxcrt/fx_string.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 enum class FDE_XmlSyntaxResult {
   None,
@@ -36,7 +36,7 @@ enum class FDE_XmlSyntaxResult {
 
 class CFDE_XMLSyntaxParser {
  public:
-  explicit CFDE_XMLSyntaxParser(const CFX_RetainPtr<IFGAS_Stream>& pStream);
+  explicit CFDE_XMLSyntaxParser(const CFX_RetainPtr<CFGAS_Stream>& pStream);
   ~CFDE_XMLSyntaxParser();
 
   FDE_XmlSyntaxResult DoSyntaxParse();
@@ -97,7 +97,7 @@ class CFDE_XMLSyntaxParser {
 
   void ParseTextChar(wchar_t ch);
 
-  CFX_RetainPtr<IFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFGAS_Stream> m_pStream;
   FX_STRSIZE m_iXMLPlaneSize;
   int32_t m_iCurrentPos;
   int32_t m_iCurrentNodeNum;
diff --git a/xfa/fde/xml/cfde_xmlsyntaxparser_unittest.cpp b/xfa/fde/xml/cfde_xmlsyntaxparser_unittest.cpp
index a45bb1276a..aecb3ee39e 100644
--- a/xfa/fde/xml/cfde_xmlsyntaxparser_unittest.cpp
+++ b/xfa/fde/xml/cfde_xmlsyntaxparser_unittest.cpp
@@ -8,8 +8,8 @@
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/test_support.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 #include "xfa/fgas/crt/fgas_codepage.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
 
 class CFDE_XMLSyntaxParserTest : public pdfium::FPDF_Test {};
 
@@ -28,9 +28,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, CData) {
       L"      app.alert(\"Tclams\");\n"
       L"  ";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -76,9 +75,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, CDataWithInnerScript) {
       L"    </script>\n"
       L"  ";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -113,9 +111,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, ArrowBangArrow) {
       "  <!>\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -148,9 +145,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, ArrowBangBracketArrow) {
       "  <![>\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -178,9 +174,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, IncompleteCData) {
       "  <![CDATA>\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -208,9 +203,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, UnClosedCData) {
       "  <![CDATA[\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -238,9 +232,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, EmptyCData) {
       "  <![CDATA[]]>\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -275,9 +268,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, Comment) {
       "  <!-- A Comment -->\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -309,9 +301,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, IncorrectCommentStart) {
       "  <!- A Comment -->\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -343,9 +334,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, CommentEmpty) {
       "  <!---->\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -377,9 +367,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, CommentThreeDash) {
       "  <!--->\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -405,9 +394,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, CommentTwoDash) {
       "  <!-->\n"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -437,9 +425,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, Entities) {
       "&#x0000000000000000000;"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -469,9 +456,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, EntityOverflowHex) {
       "&#xafffffffffffffffffffffffffffffffff;"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -501,9 +487,8 @@ TEST_F(CFDE_XMLSyntaxParserTest, EntityOverflowDecimal) {
       "&#29149102052342342134521341234512351234213452315;"
       "</script>";
 
-  CFX_RetainPtr<IFGAS_Stream> stream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input)));
+  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
+      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
diff --git a/xfa/fgas/crt/ifgas_stream.cpp b/xfa/fgas/crt/cfgas_stream.cpp
index 7a90626fe8..809c19bdae 100644
--- a/xfa/fgas/crt/ifgas_stream.cpp
+++ b/xfa/fgas/crt/cfgas_stream.cpp
@@ -4,7 +4,7 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 #if _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN32_MOBILE_ || \
     _FX_OS_ == _FX_WIN64_
@@ -12,6 +12,7 @@
 #endif
 
 #include <algorithm>
+#include <limits>
 #include <memory>
 #include <utility>
 #include <vector>
@@ -23,39 +24,6 @@
 
 namespace {
 
-class CFGAS_Stream : public IFGAS_Stream {
- public:
-  template <typename T, typename... Args>
-  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
-
-  // IFGAS_Stream
-  FX_FILESIZE GetLength() const override { return m_pStream->GetSize(); }
-  FX_FILESIZE GetPosition() override { return m_iPosition; }
-  FX_STRSIZE GetBOMLength() const override { return std::max(0, m_wBOMLength); }
-  FX_STRSIZE ReadString(wchar_t* pStr,
-                        FX_STRSIZE iMaxLength,
-                        bool* bEOS) override;
-  void Seek(FX_STREAMSEEK eSeek, FX_FILESIZE iOffset) override;
-  bool IsEOF() const override { return m_iPosition >= GetLength(); }
-  void WriteString(const CFX_WideStringC& str) override;
-  uint16_t GetCodePage() const override { return m_wCodePage; }
-  void SetCodePage(uint16_t wCodePage) override;
-
- private:
-  CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
-               bool isWriteSteam);
-  ~CFGAS_Stream() override;
-
-  FX_STRSIZE ReadData(uint8_t* pBuffer, FX_STRSIZE iBufferSize);
-  void WriteData(const CFX_WideStringC& str);
-
-  uint16_t m_wCodePage;
-  FX_STRSIZE m_wBOMLength;
-  bool m_IsWriteStream;
-  FX_FILESIZE m_iPosition;
-  CFX_RetainPtr<IFX_SeekableStream> m_pStream;
-};
-
 // Returns {src bytes consumed, dst bytes produced}.
 std::pair<FX_STRSIZE, FX_STRSIZE> UTF8Decode(const char* pSrc,
                                              FX_STRSIZE srcLen,
@@ -161,6 +129,8 @@ void SwapByteOrder(wchar_t* pStr, FX_STRSIZE iLength) {
   }
 }
 
+}  // namespace
+
 #if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
 #define BOM_MASK 0x00FFFFFF
 #define BOM_UTF8 0x00BFBBEF
@@ -190,7 +160,7 @@ CFGAS_Stream::CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
   }
 
   FX_FILESIZE iPosition = GetPosition();
-  Seek(FX_STREAMSEEK_Begin, 0);
+  Seek(CFGAS_Stream::Pos::Begin, 0);
 
   uint32_t bom;
   ReadData(reinterpret_cast<uint8_t*>(&bom), 3);
@@ -213,18 +183,21 @@ CFGAS_Stream::CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
     }
   }
 
-  Seek(FX_STREAMSEEK_Begin,
+  Seek(CFGAS_Stream::Pos::Begin,
        std::max(static_cast<FX_FILESIZE>(m_wBOMLength), iPosition));
 }
 
+CFGAS_Stream::CFGAS_Stream(uint8_t* data, FX_STRSIZE size)
+    : CFGAS_Stream(IFX_MemoryStream::Create(data, size), false) {}
+
 CFGAS_Stream::~CFGAS_Stream() {}
 
-void CFGAS_Stream::Seek(FX_STREAMSEEK eSeek, FX_FILESIZE iOffset) {
+void CFGAS_Stream::Seek(CFGAS_Stream::Pos eSeek, FX_FILESIZE iOffset) {
   switch (eSeek) {
-    case FX_STREAMSEEK_Begin:
+    case CFGAS_Stream::Pos::Begin:
       m_iPosition = iOffset;
       break;
-    case FX_STREAMSEEK_Current:
+    case CFGAS_Stream::Pos::Current:
       m_iPosition += iOffset;
       break;
   }
@@ -300,7 +273,7 @@ FX_STRSIZE CFGAS_Stream::ReadString(wchar_t* pStr,
       FX_STRSIZE iSrc = 0;
       std::tie(iSrc, iMaxLength) = UTF8Decode(
           reinterpret_cast<const char*>(buf.data()), iLen, pStr, iMaxLength);
-      Seek(FX_STREAMSEEK_Current, iSrc - iLen);
+      Seek(CFGAS_Stream::Pos::Current, iSrc - iLen);
     } else {
       iMaxLength = 0;
     }
@@ -310,48 +283,22 @@ FX_STRSIZE CFGAS_Stream::ReadString(wchar_t* pStr,
   return iMaxLength;
 }
 
-void CFGAS_Stream::WriteData(const CFX_WideStringC& str) {
-  if (!m_IsWriteStream || str.GetLength() == 0)
-    return;
-  if (m_pStream->WriteBlock(str.c_str(), m_iPosition,
-                            str.GetLength() * sizeof(wchar_t))) {
-    pdfium::base::CheckedNumeric<FX_STRSIZE> new_pos = m_iPosition;
-    new_pos += str.GetLength() * sizeof(wchar_t);
-    // TODO(dsinclair): Not sure what to do if we over flow ....
-    if (!new_pos.IsValid())
-      return;
-
-    m_iPosition = new_pos.ValueOrDie();
-  }
-}
-
 void CFGAS_Stream::WriteString(const CFX_WideStringC& str) {
-  if (!m_IsWriteStream)
-    return;
-  if (str.GetLength() == 0)
+  if (!m_IsWriteStream || str.GetLength() == 0 ||
+      m_wCodePage != FX_CODEPAGE_UTF8) {
     return;
-  if (m_wCodePage != FX_CODEPAGE_UTF8)
+  }
+  if (!m_pStream->WriteBlock(str.c_str(), m_iPosition,
+                             str.GetLength() * sizeof(wchar_t))) {
     return;
+  }
 
-  WriteData(str);
-}
-
-}  // namespace
-
-// static
-CFX_RetainPtr<IFGAS_Stream> IFGAS_Stream::CreateReadStream(
-    const CFX_RetainPtr<IFX_SeekableStream>& pFileRead) {
-  if (!pFileRead)
-    return nullptr;
-
-  return pdfium::MakeRetain<CFGAS_Stream>(pFileRead, false);
-}
-
-// static
-CFX_RetainPtr<IFGAS_Stream> IFGAS_Stream::CreateWriteStream(
-    const CFX_RetainPtr<IFX_SeekableStream>& pFileWrite) {
-  if (!pFileWrite)
-    return nullptr;
+  pdfium::base::CheckedNumeric<FX_STRSIZE> new_pos = m_iPosition;
+  new_pos += str.GetLength() * sizeof(wchar_t);
+  if (!new_pos.IsValid()) {
+    m_iPosition = std::numeric_limits<FX_STRSIZE>::max();
+    return;
+  }
 
-  return pdfium::MakeRetain<CFGAS_Stream>(pFileWrite, true);
+  m_iPosition = new_pos.ValueOrDie();
 }
diff --git a/xfa/fgas/crt/cfgas_stream.h b/xfa/fgas/crt/cfgas_stream.h
new file mode 100644
index 0000000000..5d2e5e6242
--- /dev/null
+++ b/xfa/fgas/crt/cfgas_stream.h
@@ -0,0 +1,54 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef XFA_FGAS_CRT_CFGAS_STREAM_H_
+#define XFA_FGAS_CRT_CFGAS_STREAM_H_
+
+#include <algorithm>
+
+#include "core/fxcrt/cfx_retain_ptr.h"
+#include "core/fxcrt/fx_stream.h"
+#include "core/fxcrt/fx_system.h"
+
+class CFGAS_Stream : public CFX_Retainable {
+ public:
+  enum class Pos {
+    Begin = 0,
+    Current,
+  };
+
+  template <typename T, typename... Args>
+  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
+
+  FX_FILESIZE GetLength() const { return m_pStream->GetSize(); }
+  FX_FILESIZE GetPosition() { return m_iPosition; }
+  FX_STRSIZE GetBOMLength() const { return std::max(0, m_wBOMLength); }
+  bool IsEOF() const { return m_iPosition >= GetLength(); }
+
+  void Seek(CFGAS_Stream::Pos eSeek, FX_FILESIZE iOffset);
+  FX_STRSIZE ReadString(wchar_t* pStr, FX_STRSIZE iMaxLength, bool* bEOS);
+
+  void WriteString(const CFX_WideStringC& str);
+
+  uint16_t GetCodePage() const { return m_wCodePage; }
+  void SetCodePage(uint16_t wCodePage);
+
+ private:
+  CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
+               bool isWriteSteam);
+  CFGAS_Stream(uint8_t* data, FX_STRSIZE size);
+  ~CFGAS_Stream() override;
+
+  FX_STRSIZE ReadData(uint8_t* pBuffer, FX_STRSIZE iBufferSize);
+
+  uint16_t m_wCodePage;
+  FX_STRSIZE m_wBOMLength;
+  bool m_IsWriteStream;
+  FX_FILESIZE m_iPosition;
+  CFX_RetainPtr<IFX_SeekableStream> m_pStream;
+};
+
+#endif  // XFA_FGAS_CRT_CFGAS_STREAM_H_
diff --git a/xfa/fgas/crt/ifgas_stream.h b/xfa/fgas/crt/ifgas_stream.h
deleted file mode 100644
index acc9f1c4eb..0000000000
--- a/xfa/fgas/crt/ifgas_stream.h
+++ /dev/null
@@ -1,44 +0,0 @@
-// Copyright 2014 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#ifndef XFA_FGAS_CRT_IFGAS_STREAM_H_
-#define XFA_FGAS_CRT_IFGAS_STREAM_H_
-
-#include "core/fxcrt/cfx_retain_ptr.h"
-#include "core/fxcrt/fx_stream.h"
-#include "core/fxcrt/fx_system.h"
-
-enum FX_STREAMSEEK {
-  FX_STREAMSEEK_Begin = 0,
-  FX_STREAMSEEK_Current,
-};
-
-class IFGAS_Stream : public CFX_Retainable {
- public:
-  static CFX_RetainPtr<IFGAS_Stream> CreateReadStream(
-      const CFX_RetainPtr<IFX_SeekableStream>& pFileRead);
-  static CFX_RetainPtr<IFGAS_Stream> CreateWriteStream(
-      const CFX_RetainPtr<IFX_SeekableStream>& pFileWrite);
-
-  virtual FX_FILESIZE GetLength() const = 0;
-  virtual FX_FILESIZE GetPosition() = 0;
-  virtual FX_STRSIZE GetBOMLength() const = 0;
-
-  virtual void Seek(FX_STREAMSEEK eSeek, FX_FILESIZE iOffset) = 0;
-
-  virtual FX_STRSIZE ReadString(wchar_t* pStr,
-                                FX_STRSIZE iMaxLength,
-                                bool* bEOS) = 0;
-  virtual void WriteString(const CFX_WideStringC& str) = 0;
-
-  virtual uint16_t GetCodePage() const = 0;
-  virtual void SetCodePage(uint16_t wCodePage) = 0;
-
- protected:
-  virtual bool IsEOF() const = 0;
-};
-
-#endif  // XFA_FGAS_CRT_IFGAS_STREAM_H_
diff --git a/xfa/fgas/font/cfgas_fontmgr.h b/xfa/fgas/font/cfgas_fontmgr.h
index c0b59f4dd7..8a3705335e 100644
--- a/xfa/fgas/font/cfgas_fontmgr.h
+++ b/xfa/fgas/font/cfgas_fontmgr.h
@@ -18,7 +18,7 @@
 #include "core/fxge/cfx_fontmapper.h"
 #include "core/fxge/fx_freetype.h"
 #include "core/fxge/ifx_systemfontinfo.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 
 #define FX_FONTSTYLE_Normal 0x00
 #define FX_FONTSTYLE_FixedPitch 0x01
diff --git a/xfa/fgas/font/cfgas_gefont.h b/xfa/fgas/font/cfgas_gefont.h
index 14029be1e0..6c9f2a168d 100644
--- a/xfa/fgas/font/cfgas_gefont.h
+++ b/xfa/fgas/font/cfgas_gefont.h
@@ -67,7 +67,7 @@ class CFGAS_GEFont : public CFX_Retainable {
                         uint32_t dwFontStyles,
                         uint16_t wCodePage);
   bool LoadFontInternal(const uint8_t* pBuffer, int32_t length);
-  bool LoadFontInternal(const CFX_RetainPtr<IFGAS_Stream>& pFontStream,
+  bool LoadFontInternal(const CFX_RetainPtr<CFGAS_Stream>& pFontStream,
                         bool bSaveStream);
 #endif
   bool LoadFontInternal(CFX_Font* pExternalFont);
@@ -95,7 +95,7 @@ class CFGAS_GEFont : public CFX_Retainable {
   CFX_RetainPtr<CFGAS_GEFont> m_pSrcFont;  // Only set by ctor, so no cycles.
   CFGAS_FontMgr* const m_pFontMgr;
   bool m_bExternalFont;
-  CFX_RetainPtr<IFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFGAS_Stream> m_pStream;
   CFX_RetainPtr<IFX_SeekableReadStream> m_pFileRead;
   std::unique_ptr<CFX_UnicodeEncoding> m_pFontEncoding;
   std::map<wchar_t, int32_t> m_CharWidthMap;
diff --git a/xfa/fxfa/parser/cxfa_dataexporter.cpp b/xfa/fxfa/parser/cxfa_dataexporter.cpp
index 4e3b0b3ffa..442195b1dd 100644
--- a/xfa/fxfa/parser/cxfa_dataexporter.cpp
+++ b/xfa/fxfa/parser/cxfa_dataexporter.cpp
@@ -226,8 +226,7 @@ void RegenerateFormFile_Changed(CXFA_Node* pNode,
 
         CFX_RetainPtr<IFX_MemoryStream> pMemStream =
             IFX_MemoryStream::Create(true);
-        CFX_RetainPtr<IFGAS_Stream> pTempStream =
-            IFGAS_Stream::CreateWriteStream(pMemStream);
+        auto pTempStream = pdfium::MakeRetain<CFGAS_Stream>(pMemStream, true);
 
         pTempStream->SetCodePage(FX_CODEPAGE_UTF8);
         pRichTextXML->SaveXMLNode(pTempStream);
@@ -343,8 +342,8 @@ void RegenerateFormFile_Changed(CXFA_Node* pNode,
 }
 
 void RegenerateFormFile_Container(CXFA_Node* pNode,
-                                  const CFX_RetainPtr<IFGAS_Stream>& pStream,
-                                  bool bSaveXML = false) {
+                                  const CFX_RetainPtr<CFGAS_Stream>& pStream,
+                                  bool bSaveXML) {
   XFA_Element eType = pNode->GetElementType();
   if (eType == XFA_Element::Field || eType == XFA_Element::Draw ||
       !pNode->IsContainerNode()) {
@@ -400,7 +399,7 @@ void RegenerateFormFile_Container(CXFA_Node* pNode,
 
 void XFA_DataExporter_RegenerateFormFile(
     CXFA_Node* pNode,
-    const CFX_RetainPtr<IFGAS_Stream>& pStream,
+    const CFX_RetainPtr<CFGAS_Stream>& pStream,
     const char* pChecksum,
     bool bSaveXML) {
   if (pNode->IsModelNode()) {
@@ -428,7 +427,7 @@ void XFA_DataExporter_RegenerateFormFile(
 
     CXFA_Node* pChildNode = pNode->GetNodeItem(XFA_NODEITEM_FirstChild);
     while (pChildNode) {
-      RegenerateFormFile_Container(pChildNode, pStream);
+      RegenerateFormFile_Container(pChildNode, pStream, false);
       pChildNode = pChildNode->GetNodeItem(XFA_NODEITEM_NextSibling);
     }
     pStream->WriteString(L"</form\n>");
@@ -486,15 +485,12 @@ bool CXFA_DataExporter::Export(const CFX_RetainPtr<IFX_SeekableStream>& pWrite,
   if (!pWrite)
     return false;
 
-  CFX_RetainPtr<IFGAS_Stream> pStream = IFGAS_Stream::CreateWriteStream(pWrite);
-  if (!pStream)
-    return false;
-
+  auto pStream = pdfium::MakeRetain<CFGAS_Stream>(pWrite, true);
   pStream->SetCodePage(FX_CODEPAGE_UTF8);
   return Export(pStream, pNode, dwFlag, pChecksum);
 }
 
-bool CXFA_DataExporter::Export(const CFX_RetainPtr<IFGAS_Stream>& pStream,
+bool CXFA_DataExporter::Export(const CFX_RetainPtr<CFGAS_Stream>& pStream,
                                CXFA_Node* pNode,
                                uint32_t dwFlag,
                                const char* pChecksum) {
diff --git a/xfa/fxfa/parser/cxfa_dataexporter.h b/xfa/fxfa/parser/cxfa_dataexporter.h
index 8f405b188d..c7e5c7b70b 100644
--- a/xfa/fxfa/parser/cxfa_dataexporter.h
+++ b/xfa/fxfa/parser/cxfa_dataexporter.h
@@ -13,7 +13,7 @@
 class CXFA_Document;
 class CXFA_Node;
 class IFX_SeekableStream;
-class IFGAS_Stream;
+class CFGAS_Stream;
 
 class CXFA_DataExporter {
  public:
@@ -26,7 +26,7 @@ class CXFA_DataExporter {
               const char* pChecksum);
 
  private:
-  bool Export(const CFX_RetainPtr<IFGAS_Stream>& pStream,
+  bool Export(const CFX_RetainPtr<CFGAS_Stream>& pStream,
               CXFA_Node* pNode,
               uint32_t dwFlag,
               const char* pChecksum);
diff --git a/xfa/fxfa/parser/cxfa_node.cpp b/xfa/fxfa/parser/cxfa_node.cpp
index 90e93fbda5..26dc6bd831 100644
--- a/xfa/fxfa/parser/cxfa_node.cpp
+++ b/xfa/fxfa/parser/cxfa_node.cpp
@@ -1408,14 +1408,7 @@ void CXFA_Node::Script_NodeClass_SaveXML(CFXJSE_Arguments* pArguments) {
     }
     CFX_RetainPtr<IFX_MemoryStream> pMemoryStream =
         IFX_MemoryStream::Create(true);
-    CFX_RetainPtr<IFGAS_Stream> pStream =
-        IFGAS_Stream::CreateWriteStream(pMemoryStream);
-
-    if (!pStream) {
-      pArguments->GetReturnValue()->SetString(
-          bsXMLHeader.UTF8Encode().AsStringC());
-      return;
-    }
+    auto pStream = pdfium::MakeRetain<CFGAS_Stream>(pMemoryStream, true);
     pStream->SetCodePage(FX_CODEPAGE_UTF8);
     pStream->WriteString(bsXMLHeader.AsStringC());
 
diff --git a/xfa/fxfa/parser/cxfa_simple_parser.cpp b/xfa/fxfa/parser/cxfa_simple_parser.cpp
index 1ebed10b4d..92196ec957 100644
--- a/xfa/fxfa/parser/cxfa_simple_parser.cpp
+++ b/xfa/fxfa/parser/cxfa_simple_parser.cpp
@@ -19,8 +19,8 @@
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmlparser.h"
 #include "xfa/fde/xml/cfde_xmltext.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 #include "xfa/fgas/crt/fgas_codepage.h"
-#include "xfa/fgas/crt/ifgas_stream.h"
 #include "xfa/fxfa/fxfa.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
@@ -277,10 +277,7 @@ int32_t CXFA_SimpleParser::StartParse(
     XFA_XDPPACKET ePacketID) {
   CloseParser();
   m_pFileRead = pStream;
-  m_pStream = IFGAS_Stream::CreateReadStream(pStream);
-  if (!m_pStream)
-    return XFA_PARSESTATUS_StreamErr;
-
+  m_pStream = pdfium::MakeRetain<CFGAS_Stream>(pStream, false);
   uint16_t wCodePage = m_pStream->GetCodePage();
   if (wCodePage != FX_CODEPAGE_UTF16LE && wCodePage != FX_CODEPAGE_UTF16BE &&
       wCodePage != FX_CODEPAGE_UTF8) {
@@ -322,9 +319,8 @@ CFDE_XMLNode* CXFA_SimpleParser::ParseXMLData(const CFX_ByteString& wsXML,
   CloseParser();
   m_pXMLDoc = pdfium::MakeUnique<CFDE_XMLDoc>();
 
-  CFX_RetainPtr<IFGAS_Stream> pStream =
-      IFGAS_Stream::CreateReadStream(IFX_MemoryStream::Create(
-          const_cast<uint8_t*>(wsXML.raw_str()), wsXML.GetLength()));
+  auto pStream = pdfium::MakeRetain<CFGAS_Stream>(
+      const_cast<uint8_t*>(wsXML.raw_str()), wsXML.GetLength());
   auto pParser =
       pdfium::MakeUnique<CFDE_XMLParser>(m_pXMLDoc->GetRoot(), pStream);
   pParser->m_dwCheckStatus = 0x03;
diff --git a/xfa/fxfa/parser/cxfa_simple_parser.h b/xfa/fxfa/parser/cxfa_simple_parser.h
index 7671e8d740..32b5518fab 100644
--- a/xfa/fxfa/parser/cxfa_simple_parser.h
+++ b/xfa/fxfa/parser/cxfa_simple_parser.h
@@ -19,7 +19,7 @@ class CFDE_XMLNode;
 class CFDE_XMLParser;
 class IFX_SeekableStream;
 class IFX_Pause;
-class IFGAS_Stream;
+class CFGAS_Stream;
 
 class CXFA_SimpleParser {
  public:
@@ -78,7 +78,7 @@ class CXFA_SimpleParser {
 
   CFDE_XMLParser* m_pXMLParser;
   std::unique_ptr<CFDE_XMLDoc> m_pXMLDoc;
-  CFX_RetainPtr<IFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFGAS_Stream> m_pStream;
   CFX_RetainPtr<IFX_SeekableStream> m_pFileRead;
   CXFA_Document* m_pFactory;
   CXFA_Node* m_pRootNode;
diff --git a/xfa/fxfa/parser/xfa_utils.h b/xfa/fxfa/parser/xfa_utils.h
index 36d62c7602..ae51c8fdc6 100644
--- a/xfa/fxfa/parser/xfa_utils.h
+++ b/xfa/fxfa/parser/xfa_utils.h
@@ -7,7 +7,7 @@
 #ifndef XFA_FXFA_PARSER_XFA_UTILS_H_
 #define XFA_FXFA_PARSER_XFA_UTILS_H_
 
-#include "xfa/fgas/crt/ifgas_stream.h"
+#include "xfa/fgas/crt/cfgas_stream.h"
 #include "xfa/fxfa/fxfa_basic.h"
 
 class CFDE_XMLElement;
@@ -155,7 +155,7 @@ bool XFA_FieldIsMultiListBox(CXFA_Node* pFieldNode);
 void XFA_DataExporter_DealWithDataGroupNode(CXFA_Node* pDataNode);
 void XFA_DataExporter_RegenerateFormFile(
     CXFA_Node* pNode,
-    const CFX_RetainPtr<IFGAS_Stream>& pStream,
+    const CFX_RetainPtr<CFGAS_Stream>& pStream,
     const char* pChecksum = nullptr,
     bool bSaveXML = false);