Move CFGAS_Stream to CFX_SeekableStreamProxy

This CL moves the FGAS stream code into core/fxcrt and renames to
CFX_SeekableStreamProxy.

Change-Id: I6641fe0cca45a128ef3ec281b0b40f8d60296387
Reviewed-on: https://pdfium-review.googlesource.com/4311
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>

32 files changed, 116 insertions, 587 deletions

diff --git a/xfa/fde/cfde_txtedtengine.cpp b/xfa/fde/cfde_txtedtengine.cpp
index 136735c16e..762c16f4c9 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<CFGAS_Stream>& pStream) {
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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(CFGAS_Stream::Pos::Begin, nPos);
+      pStream->Seek(CFX_SeekableStreamProxy::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 bbdef8fd7a..4a54c6df98 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<CFGAS_Stream>& pStream);
+  void SetTextByStream(const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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_cssstylesheet.cpp b/xfa/fde/css/cfde_cssstylesheet.cpp
index 175289be11..c16e25156c 100644
--- a/xfa/fde/css/cfde_cssstylesheet.cpp
+++ b/xfa/fde/css/cfde_cssstylesheet.cpp
@@ -8,12 +8,12 @@
 
 #include <utility>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/stl_util.h"
 #include "xfa/fde/css/cfde_cssdeclaration.h"
 #include "xfa/fde/css/cfde_cssstylerule.h"
 #include "xfa/fde/css/fde_cssdatatable.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 
 CFDE_CSSStyleSheet::CFDE_CSSStyleSheet() {}
 
diff --git a/xfa/fde/css/cfde_csssyntaxparser.cpp b/xfa/fde/css/cfde_csssyntaxparser.cpp
index 9c45422ebb..ac1abcc665 100644
--- a/xfa/fde/css/cfde_csssyntaxparser.cpp
+++ b/xfa/fde/css/cfde_csssyntaxparser.cpp
@@ -8,9 +8,9 @@
 
 #include <algorithm>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "xfa/fde/css/cfde_cssdeclaration.h"
 #include "xfa/fde/css/fde_cssdatatable.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 
 namespace {
 
diff --git a/xfa/fde/css/cfde_csstextbuf.h b/xfa/fde/css/cfde_csstextbuf.h
index 43ff03aa07..71c76f3361 100644
--- a/xfa/fde/css/cfde_csstextbuf.h
+++ b/xfa/fde/css/cfde_csstextbuf.h
@@ -8,9 +8,9 @@
 #define XFA_FDE_CSS_CFDE_CSSTEXTBUF_H_
 
 #include "core/fxcrt/cfx_retain_ptr.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
 #include "core/fxcrt/fx_memory.h"
 #include "core/fxcrt/fx_system.h"
-#include "xfa/fgas/crt/cfgas_stream.h"
 
 class CFDE_CSSTextBuf {
  public:
diff --git a/xfa/fde/css/fde_css.h b/xfa/fde/css/fde_css.h
index 9e56fce59a..ac44e30175 100644
--- a/xfa/fde/css/fde_css.h
+++ b/xfa/fde/css/fde_css.h
@@ -7,8 +7,8 @@
 #ifndef XFA_FDE_CSS_FDE_CSS_H_
 #define XFA_FDE_CSS_FDE_CSS_H_
 
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
 #include "core/fxge/fx_dib.h"
-#include "xfa/fgas/crt/cfgas_stream.h"
 #include "xfa/fgas/font/cfgas_fontmgr.h"
 
 enum FDE_CSSVALUETYPE {
diff --git a/xfa/fde/css/fde_cssdatatable.cpp b/xfa/fde/css/fde_cssdatatable.cpp
index d61c610fe9..5fa9cf0dc9 100644
--- a/xfa/fde/css/fde_cssdatatable.cpp
+++ b/xfa/fde/css/fde_cssdatatable.cpp
@@ -8,10 +8,10 @@
 
 #include <utility>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_ext.h"
 #include "xfa/fde/css/cfde_cssstyleselector.h"
 #include "xfa/fde/css/cfde_cssvaluelistparser.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 
 static const FDE_CSSPropertyTable g_FDE_CSSProperties[] = {
     {FDE_CSSProperty::BorderLeft, L"border-left", 0x04080036,
diff --git a/xfa/fde/xml/cfde_xmldoc.cpp b/xfa/fde/xml/cfde_xmldoc.cpp
index 256164c5f8..fa44472098 100644
--- a/xfa/fde/xml/cfde_xmldoc.cpp
+++ b/xfa/fde/xml/cfde_xmldoc.cpp
@@ -9,6 +9,7 @@
 #include <utility>
 #include <vector>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/stl_util.h"
 #include "xfa/fde/xml/cfde_xmlchardata.h"
@@ -16,7 +17,6 @@
 #include "xfa/fde/xml/cfde_xmlinstruction.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmltext.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 
 CFDE_XMLDoc::CFDE_XMLDoc()
     : m_iStatus(0), m_pRoot(pdfium::MakeUnique<CFDE_XMLNode>()) {
@@ -47,8 +47,9 @@ void CFDE_XMLDoc::CloseXML() {
   m_pXMLParser.reset();
 }
 
-void CFDE_XMLDoc::SaveXMLNode(const CFX_RetainPtr<CFGAS_Stream>& pXMLStream,
-                              CFDE_XMLNode* pINode) {
+void CFDE_XMLDoc::SaveXMLNode(
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& pXMLStream,
+    CFDE_XMLNode* pINode) {
   CFDE_XMLNode* pNode = (CFDE_XMLNode*)pINode;
   switch (pNode->GetType()) {
     case FDE_XMLNODE_Instruction: {
diff --git a/xfa/fde/xml/cfde_xmldoc.h b/xfa/fde/xml/cfde_xmldoc.h
index b84c9c00a0..c9c7db41b7 100644
--- a/xfa/fde/xml/cfde_xmldoc.h
+++ b/xfa/fde/xml/cfde_xmldoc.h
@@ -10,9 +10,9 @@
 #include <memory>
 
 #include "core/fxcrt/cfx_retain_ptr.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmlparser.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<CFGAS_Stream>& pXMLStream,
+  void SaveXMLNode(const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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<CFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFX_SeekableStreamProxy> 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 149d18c3d6..c81de7623a 100644
--- a/xfa/fde/xml/cfde_xmlnode.cpp
+++ b/xfa/fde/xml/cfde_xmlnode.cpp
@@ -8,12 +8,12 @@
 
 #include <vector>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "third_party/base/stl_util.h"
 #include "xfa/fde/xml/cfde_xmlchardata.h"
 #include "xfa/fde/xml/cfde_xmlelement.h"
 #include "xfa/fde/xml/cfde_xmlinstruction.h"
 #include "xfa/fde/xml/cfde_xmltext.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 
 CFDE_XMLNode::CFDE_XMLNode()
     : m_pParent(nullptr),
@@ -329,7 +329,8 @@ std::unique_ptr<CFDE_XMLNode> CFDE_XMLNode::Clone() {
   return nullptr;
 }
 
-void CFDE_XMLNode::SaveXMLNode(const CFX_RetainPtr<CFGAS_Stream>& pXMLStream) {
+void CFDE_XMLNode::SaveXMLNode(
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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 a04bd8c812..71e1a712e0 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/cfgas_stream.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.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<CFGAS_Stream>& pXMLStream);
+  void SaveXMLNode(const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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 c29dfc38ab..c8b300f81d 100644
--- a/xfa/fde/xml/cfde_xmlparser.cpp
+++ b/xfa/fde/xml/cfde_xmlparser.cpp
@@ -14,8 +14,9 @@
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmltext.h"
 
-CFDE_XMLParser::CFDE_XMLParser(CFDE_XMLNode* pParent,
-                               const CFX_RetainPtr<CFGAS_Stream>& pStream)
+CFDE_XMLParser::CFDE_XMLParser(
+    CFDE_XMLNode* pParent,
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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 f1a7888fa7..14b2127068 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 CFGAS_Stream;
+class CFX_SeekableStreamProxy;
 class IFX_Pause;
 
 class CFDE_XMLParser {
  public:
   CFDE_XMLParser(CFDE_XMLNode* pParent,
-                 const CFX_RetainPtr<CFGAS_Stream>& pStream);
+                 const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream);
   ~CFDE_XMLParser();
 
   int32_t DoParser(IFX_Pause* pPause);
@@ -34,7 +34,7 @@ class CFDE_XMLParser {
   uint16_t m_dwCurrentCheckStatus;
 
  private:
-  CFX_RetainPtr<CFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFX_SeekableStreamProxy> 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 10eefdc012..5d671bb39a 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<CFGAS_Stream>& pStream)
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream)
     : m_pStream(pStream),
       m_iXMLPlaneSize(32 * 1024),
       m_iCurrentPos(0),
@@ -145,7 +145,7 @@ FDE_XmlSyntaxResult CFDE_XMLSyntaxParser::DoSyntaxParse() {
       m_ParsedChars += m_End;
       m_iParsedBytes = m_iCurrentPos;
       if (m_pStream->GetPosition() != m_iCurrentPos)
-        m_pStream->Seek(CFGAS_Stream::Pos::Begin, m_iCurrentPos);
+        m_pStream->Seek(CFX_SeekableStreamProxy::Pos::Begin, m_iCurrentPos);
 
       m_iBufferChars =
           m_pStream->ReadString(m_Buffer.data(), m_iXMLPlaneSize, &m_bEOS);
diff --git a/xfa/fde/xml/cfde_xmlsyntaxparser.h b/xfa/fde/xml/cfde_xmlsyntaxparser.h
index aa4e91827e..8b6c9ac8b5 100644
--- a/xfa/fde/xml/cfde_xmlsyntaxparser.h
+++ b/xfa/fde/xml/cfde_xmlsyntaxparser.h
@@ -12,9 +12,9 @@
 
 #include "core/fxcrt/cfx_blockbuffer.h"
 #include "core/fxcrt/cfx_retain_ptr.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
 #include "core/fxcrt/fx_string.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
-#include "xfa/fgas/crt/cfgas_stream.h"
 
 enum class FDE_XmlSyntaxResult {
   None,
@@ -36,7 +36,8 @@ enum class FDE_XmlSyntaxResult {
 
 class CFDE_XMLSyntaxParser {
  public:
-  explicit CFDE_XMLSyntaxParser(const CFX_RetainPtr<CFGAS_Stream>& pStream);
+  explicit CFDE_XMLSyntaxParser(
+      const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream);
   ~CFDE_XMLSyntaxParser();
 
   FDE_XmlSyntaxResult DoSyntaxParse();
@@ -97,7 +98,7 @@ class CFDE_XMLSyntaxParser {
 
   void ParseTextChar(wchar_t ch);
 
-  CFX_RetainPtr<CFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFX_SeekableStreamProxy> 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 aecb3ee39e..45ad3bb2f0 100644
--- a/xfa/fde/xml/cfde_xmlsyntaxparser_unittest.cpp
+++ b/xfa/fde/xml/cfde_xmlsyntaxparser_unittest.cpp
@@ -6,10 +6,10 @@
 
 #include <memory>
 
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
+#include "core/fxcrt/fx_codepage.h"
 #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"
 
 class CFDE_XMLSyntaxParserTest : public pdfium::FPDF_Test {};
 
@@ -28,8 +28,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, CData) {
       L"      app.alert(\"Tclams\");\n"
       L"  ";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -75,8 +76,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, CDataWithInnerScript) {
       L"    </script>\n"
       L"  ";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -111,8 +113,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, ArrowBangArrow) {
       "  <!>\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -145,8 +148,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, ArrowBangBracketArrow) {
       "  <![>\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -174,8 +178,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, IncompleteCData) {
       "  <![CDATA>\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -203,8 +208,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, UnClosedCData) {
       "  <![CDATA[\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -232,8 +238,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, EmptyCData) {
       "  <![CDATA[]]>\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -268,8 +275,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, Comment) {
       "  <!-- A Comment -->\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -301,8 +309,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, IncorrectCommentStart) {
       "  <!- A Comment -->\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -334,8 +343,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, CommentEmpty) {
       "  <!---->\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -367,8 +377,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, CommentThreeDash) {
       "  <!--->\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -394,8 +405,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, CommentTwoDash) {
       "  <!-->\n"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -425,8 +437,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, Entities) {
       "&#x0000000000000000000;"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -456,8 +469,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, EntityOverflowHex) {
       "&#xafffffffffffffffffffffffffffffffff;"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
   stream->SetCodePage(FX_CODEPAGE_UTF8);
 
   CFDE_XMLSyntaxParser parser(stream);
@@ -487,8 +501,9 @@ TEST_F(CFDE_XMLSyntaxParserTest, EntityOverflowDecimal) {
       "&#29149102052342342134521341234512351234213452315;"
       "</script>";
 
-  CFX_RetainPtr<CFGAS_Stream> stream = pdfium::MakeRetain<CFGAS_Stream>(
-      reinterpret_cast<uint8_t*>(const_cast<char*>(input)), strlen(input));
+  CFX_RetainPtr<CFX_SeekableStreamProxy> stream =
+      pdfium::MakeRetain<CFX_SeekableStreamProxy>(
+          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/cfgas_stream.cpp b/xfa/fgas/crt/cfgas_stream.cpp
deleted file mode 100644
index 809c19bdae..0000000000
--- a/xfa/fgas/crt/cfgas_stream.cpp
+++ /dev/null
@@ -1,304 +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
-
-#include "xfa/fgas/crt/cfgas_stream.h"
-
-#if _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN32_MOBILE_ || \
-    _FX_OS_ == _FX_WIN64_
-#include <io.h>
-#endif
-
-#include <algorithm>
-#include <limits>
-#include <memory>
-#include <utility>
-#include <vector>
-
-#include "core/fxcrt/fx_ext.h"
-#include "third_party/base/ptr_util.h"
-#include "third_party/base/stl_util.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
-
-namespace {
-
-// Returns {src bytes consumed, dst bytes produced}.
-std::pair<FX_STRSIZE, FX_STRSIZE> UTF8Decode(const char* pSrc,
-                                             FX_STRSIZE srcLen,
-                                             wchar_t* pDst,
-                                             FX_STRSIZE dstLen) {
-  ASSERT(pDst && dstLen > 0);
-
-  if (srcLen < 1)
-    return {0, 0};
-
-  uint32_t dwCode = 0;
-  int32_t iPending = 0;
-  FX_STRSIZE iSrcNum = 0;
-  FX_STRSIZE iDstNum = 0;
-  FX_STRSIZE iIndex = 0;
-  int32_t k = 1;
-  while (iIndex < srcLen) {
-    uint8_t byte = static_cast<uint8_t>(*(pSrc + iIndex));
-    if (byte < 0x80) {
-      iPending = 0;
-      k = 1;
-      iDstNum++;
-      iSrcNum += k;
-      *pDst++ = byte;
-      if (iDstNum >= dstLen)
-        break;
-    } else if (byte < 0xc0) {
-      if (iPending < 1)
-        break;
-
-      iPending--;
-      dwCode |= (byte & 0x3f) << (iPending * 6);
-      if (iPending == 0) {
-        iDstNum++;
-        iSrcNum += k;
-        *pDst++ = dwCode;
-        if (iDstNum >= dstLen)
-          break;
-      }
-    } else if (byte < 0xe0) {
-      iPending = 1;
-      k = 2;
-      dwCode = (byte & 0x1f) << 6;
-    } else if (byte < 0xf0) {
-      iPending = 2;
-      k = 3;
-      dwCode = (byte & 0x0f) << 12;
-    } else if (byte < 0xf8) {
-      iPending = 3;
-      k = 4;
-      dwCode = (byte & 0x07) << 18;
-    } else if (byte < 0xfc) {
-      iPending = 4;
-      k = 5;
-      dwCode = (byte & 0x03) << 24;
-    } else if (byte < 0xfe) {
-      iPending = 5;
-      k = 6;
-      dwCode = (byte & 0x01) << 30;
-    } else {
-      break;
-    }
-    iIndex++;
-  }
-  return {iSrcNum, iDstNum};
-}
-
-void UTF16ToWChar(void* pBuffer, FX_STRSIZE iLength) {
-  ASSERT(pBuffer && iLength > 0);
-
-  if (sizeof(wchar_t) == 2)
-    return;
-
-  uint16_t* pSrc = static_cast<uint16_t*>(pBuffer);
-  wchar_t* pDst = static_cast<wchar_t*>(pBuffer);
-  while (--iLength >= 0)
-    pDst[iLength] = static_cast<wchar_t>(pSrc[iLength]);
-}
-
-void SwapByteOrder(wchar_t* pStr, FX_STRSIZE iLength) {
-  ASSERT(pStr);
-
-  if (iLength < 0)
-    iLength = FXSYS_wcslen(pStr);
-
-  uint16_t wch;
-  if (sizeof(wchar_t) > 2) {
-    while (iLength-- > 0) {
-      wch = static_cast<uint16_t>(*pStr);
-      wch = (wch >> 8) | (wch << 8);
-      wch &= 0x00FF;
-      *pStr = wch;
-      ++pStr;
-    }
-    return;
-  }
-
-  while (iLength-- > 0) {
-    wch = static_cast<uint16_t>(*pStr);
-    wch = (wch >> 8) | (wch << 8);
-    *pStr = wch;
-    ++pStr;
-  }
-}
-
-}  // namespace
-
-#if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-#define BOM_MASK 0x00FFFFFF
-#define BOM_UTF8 0x00BFBBEF
-#define BOM_UTF16_MASK 0x0000FFFF
-#define BOM_UTF16_BE 0x0000FFFE
-#define BOM_UTF16_LE 0x0000FEFF
-#else
-#define BOM_MASK 0xFFFFFF00
-#define BOM_UTF8 0xEFBBBF00
-#define BOM_UTF16_MASK 0xFFFF0000
-#define BOM_UTF16_BE 0xFEFF0000
-#define BOM_UTF16_LE 0xFFFE0000
-#endif  // _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-
-CFGAS_Stream::CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
-                           bool isWriteStream)
-    : m_wCodePage(FX_CODEPAGE_DefANSI),
-      m_wBOMLength(0),
-      m_IsWriteStream(isWriteStream),
-      m_iPosition(0),
-      m_pStream(stream) {
-  ASSERT(m_pStream);
-
-  if (isWriteStream) {
-    m_iPosition = m_pStream->GetSize();
-    return;
-  }
-
-  FX_FILESIZE iPosition = GetPosition();
-  Seek(CFGAS_Stream::Pos::Begin, 0);
-
-  uint32_t bom;
-  ReadData(reinterpret_cast<uint8_t*>(&bom), 3);
-
-  bom &= BOM_MASK;
-  if (bom == BOM_UTF8) {
-    m_wBOMLength = 3;
-    m_wCodePage = FX_CODEPAGE_UTF8;
-  } else {
-    bom &= BOM_UTF16_MASK;
-    if (bom == BOM_UTF16_BE) {
-      m_wBOMLength = 2;
-      m_wCodePage = FX_CODEPAGE_UTF16BE;
-    } else if (bom == BOM_UTF16_LE) {
-      m_wBOMLength = 2;
-      m_wCodePage = FX_CODEPAGE_UTF16LE;
-    } else {
-      m_wBOMLength = 0;
-      m_wCodePage = FXSYS_GetACP();
-    }
-  }
-
-  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(CFGAS_Stream::Pos eSeek, FX_FILESIZE iOffset) {
-  switch (eSeek) {
-    case CFGAS_Stream::Pos::Begin:
-      m_iPosition = iOffset;
-      break;
-    case CFGAS_Stream::Pos::Current:
-      m_iPosition += iOffset;
-      break;
-  }
-  m_iPosition =
-      pdfium::clamp(m_iPosition, static_cast<FX_FILESIZE>(0), GetLength());
-}
-
-void CFGAS_Stream::SetCodePage(uint16_t wCodePage) {
-  if (m_wBOMLength > 0)
-    return;
-  m_wCodePage = wCodePage;
-}
-
-FX_STRSIZE CFGAS_Stream::ReadData(uint8_t* pBuffer, FX_STRSIZE iBufferSize) {
-  ASSERT(pBuffer && iBufferSize > 0);
-
-  if (m_IsWriteStream)
-    return -1;
-
-  iBufferSize = std::min(
-      iBufferSize, static_cast<FX_STRSIZE>(m_pStream->GetSize() - m_iPosition));
-  if (iBufferSize <= 0)
-    return 0;
-
-  if (m_pStream->ReadBlock(pBuffer, m_iPosition, iBufferSize)) {
-    pdfium::base::CheckedNumeric<FX_FILESIZE> new_pos = m_iPosition;
-    new_pos += iBufferSize;
-    if (!new_pos.IsValid())
-      return 0;
-
-    m_iPosition = new_pos.ValueOrDie();
-    return iBufferSize;
-  }
-  return 0;
-}
-
-FX_STRSIZE CFGAS_Stream::ReadString(wchar_t* pStr,
-                                    FX_STRSIZE iMaxLength,
-                                    bool* bEOS) {
-  ASSERT(pStr && iMaxLength > 0);
-
-  if (m_IsWriteStream)
-    return -1;
-
-  if (m_wCodePage == FX_CODEPAGE_UTF16LE ||
-      m_wCodePage == FX_CODEPAGE_UTF16BE) {
-    FX_FILESIZE iBytes = iMaxLength * 2;
-    FX_STRSIZE iLen = ReadData(reinterpret_cast<uint8_t*>(pStr), iBytes);
-    iMaxLength = iLen / 2;
-    if (sizeof(wchar_t) > 2)
-      UTF16ToWChar(pStr, iMaxLength);
-
-#if _FX_ENDIAN_ == _FX_BIG_ENDIAN_
-    if (m_wCodePage == FX_CODEPAGE_UTF16LE)
-      SwapByteOrder(pStr, iMaxLength);
-#else
-    if (m_wCodePage == FX_CODEPAGE_UTF16BE)
-      SwapByteOrder(pStr, iMaxLength);
-#endif
-
-  } else {
-    FX_FILESIZE pos = GetPosition();
-    FX_STRSIZE iBytes =
-        std::min(iMaxLength, static_cast<FX_STRSIZE>(GetLength() - pos));
-
-    if (iBytes > 0) {
-      std::vector<uint8_t> buf(iBytes);
-
-      FX_STRSIZE iLen = ReadData(buf.data(), iBytes);
-      if (m_wCodePage != FX_CODEPAGE_UTF8)
-        return -1;
-
-      FX_STRSIZE iSrc = 0;
-      std::tie(iSrc, iMaxLength) = UTF8Decode(
-          reinterpret_cast<const char*>(buf.data()), iLen, pStr, iMaxLength);
-      Seek(CFGAS_Stream::Pos::Current, iSrc - iLen);
-    } else {
-      iMaxLength = 0;
-    }
-  }
-
-  *bEOS = IsEOF();
-  return iMaxLength;
-}
-
-void CFGAS_Stream::WriteString(const CFX_WideStringC& str) {
-  if (!m_IsWriteStream || str.GetLength() == 0 ||
-      m_wCodePage != FX_CODEPAGE_UTF8) {
-    return;
-  }
-  if (!m_pStream->WriteBlock(str.c_str(), m_iPosition,
-                             str.GetLength() * sizeof(wchar_t))) {
-    return;
-  }
-
-  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;
-  }
-
-  m_iPosition = new_pos.ValueOrDie();
-}
diff --git a/xfa/fgas/crt/cfgas_stream.h b/xfa/fgas/crt/cfgas_stream.h
deleted file mode 100644
index 5d2e5e6242..0000000000
--- a/xfa/fgas/crt/cfgas_stream.h
+++ /dev/null
@@ -1,54 +0,0 @@
-// 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/fgas_codepage.h b/xfa/fgas/crt/fgas_codepage.h
deleted file mode 100644
index 17813595e6..0000000000
--- a/xfa/fgas/crt/fgas_codepage.h
+++ /dev/null
@@ -1,137 +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_FGAS_CODEPAGE_H_
-#define XFA_FGAS_CRT_FGAS_CODEPAGE_H_
-
-#include "core/fxcrt/fx_basic.h"
-
-#define FX_CODEPAGE_DefANSI 0
-#define FX_CODEPAGE_DefOEM 1
-#define FX_CODEPAGE_DefMAC 2
-#define FX_CODEPAGE_Thread 3
-#define FX_CODEPAGE_Symbol 42
-#define FX_CODEPAGE_MSDOS_US 437
-#define FX_CODEPAGE_Arabic_ASMO708 708
-#define FX_CODEPAGE_Arabic_ASMO449Plus 709
-#define FX_CODEPAGE_Arabic_Transparent 710
-#define FX_CODEPAGE_Arabic_NafithaEnhanced 711
-#define FX_CODEPAGE_Arabic_TransparentASMO 720
-#define FX_CODEPAGE_MSDOS_Greek1 737
-#define FX_CODEPAGE_MSDOS_Baltic 775
-#define FX_CODEPAGE_MSWin31_WesternEuropean 819
-#define FX_CODEPAGE_MSDOS_WesternEuropean 850
-#define FX_CODEPAGE_MSDOS_EasternEuropean 852
-#define FX_CODEPAGE_MSDOS_Latin3 853
-#define FX_CODEPAGE_MSDOS_Cyrillic 855
-#define FX_CODEPAGE_MSDOS_Turkish 857
-#define FX_CODEPAGE_MSDOS_Latin1Euro 858
-#define FX_CODEPAGE_MSDOS_Portuguese 860
-#define FX_CODEPAGE_MSDOS_Icelandic 861
-#define FX_CODEPAGE_MSDOS_Hebrew 862
-#define FX_CODEPAGE_MSDOS_FrenchCanadian 863
-#define FX_CODEPAGE_MSDOS_Arabic 864
-#define FX_CODEPAGE_MSDOS_Norwegian 865
-#define FX_CODEPAGE_MSDOS_Russian 866
-#define FX_CODEPAGE_MSDOS_Greek2 869
-#define FX_CODEPAGE_MSDOS_Thai 874
-#define FX_CODEPAGE_MSDOS_KamenickyCS 895
-#define FX_CODEPAGE_ShiftJIS 932
-#define FX_CODEPAGE_ChineseSimplified 936
-#define FX_CODEPAGE_Korean 949
-#define FX_CODEPAGE_ChineseTraditional 950
-#define FX_CODEPAGE_UTF16LE 1200
-#define FX_CODEPAGE_UTF16BE 1201
-#define FX_CODEPAGE_MSWin_EasternEuropean 1250
-#define FX_CODEPAGE_MSWin_Cyrillic 1251
-#define FX_CODEPAGE_MSWin_WesternEuropean 1252
-#define FX_CODEPAGE_MSWin_Greek 1253
-#define FX_CODEPAGE_MSWin_Turkish 1254
-#define FX_CODEPAGE_MSWin_Hebrew 1255
-#define FX_CODEPAGE_MSWin_Arabic 1256
-#define FX_CODEPAGE_MSWin_Baltic 1257
-#define FX_CODEPAGE_MSWin_Vietnamese 1258
-#define FX_CODEPAGE_Johab 1361
-#define FX_CODEPAGE_MAC_Roman 10000
-#define FX_CODEPAGE_MAC_ShiftJIS 10001
-#define FX_CODEPAGE_MAC_ChineseTraditional 10002
-#define FX_CODEPAGE_MAC_Korean 10003
-#define FX_CODEPAGE_MAC_Arabic 10004
-#define FX_CODEPAGE_MAC_Hebrew 10005
-#define FX_CODEPAGE_MAC_Greek 10006
-#define FX_CODEPAGE_MAC_Cyrillic 10007
-#define FX_CODEPAGE_MAC_ChineseSimplified 10008
-#define FX_CODEPAGE_MAC_Thai 10021
-#define FX_CODEPAGE_MAC_EasternEuropean 10029
-#define FX_CODEPAGE_MAC_Turkish 10081
-#define FX_CODEPAGE_UTF32LE 12000
-#define FX_CODEPAGE_UTF32BE 12001
-#define FX_CODEPAGE_ISO8859_1 28591
-#define FX_CODEPAGE_ISO8859_2 28592
-#define FX_CODEPAGE_ISO8859_3 28593
-#define FX_CODEPAGE_ISO8859_4 28594
-#define FX_CODEPAGE_ISO8859_5 28595
-#define FX_CODEPAGE_ISO8859_6 28596
-#define FX_CODEPAGE_ISO8859_7 28597
-#define FX_CODEPAGE_ISO8859_8 28598
-#define FX_CODEPAGE_ISO8859_9 28599
-#define FX_CODEPAGE_ISO8859_10 28600
-#define FX_CODEPAGE_ISO8859_11 28601
-#define FX_CODEPAGE_ISO8859_12 28602
-#define FX_CODEPAGE_ISO8859_13 28603
-#define FX_CODEPAGE_ISO8859_14 28604
-#define FX_CODEPAGE_ISO8859_15 28605
-#define FX_CODEPAGE_ISO8859_16 28606
-#define FX_CODEPAGE_ISCII_Devanagari 57002
-#define FX_CODEPAGE_ISCII_Bengali 57003
-#define FX_CODEPAGE_ISCII_Tamil 57004
-#define FX_CODEPAGE_ISCII_Telugu 57005
-#define FX_CODEPAGE_ISCII_Assamese 57006
-#define FX_CODEPAGE_ISCII_Oriya 57007
-#define FX_CODEPAGE_ISCII_Kannada 57008
-#define FX_CODEPAGE_ISCII_Malayalam 57009
-#define FX_CODEPAGE_ISCII_Gujarati 57010
-#define FX_CODEPAGE_ISCII_Punjabi 57011
-#define FX_CODEPAGE_UTF7 65000
-#define FX_CODEPAGE_UTF8 65001
-
-#define FX_CHARSET_ANSI 0
-#define FX_CHARSET_Default 1
-#define FX_CHARSET_Symbol 2
-#define FX_CHARSET_MAC_Roman 77
-#define FX_CHARSET_MAC_ShiftJIS 78
-#define FX_CHARSET_MAC_Korean 79
-#define FX_CHARSET_MAC_ChineseSimplified 80
-#define FX_CHARSET_MAC_ChineseTriditional 81
-#define FX_CHARSET_MAC_Johab 82
-#define FX_CHARSET_MAC_Hebrew 83
-#define FX_CHARSET_MAC_Arabic 84
-#define FX_CHARSET_MAC_Greek 85
-#define FX_CHARSET_MAC_Turkish 86
-#define FX_CHARSET_MAC_Thai 87
-#define FX_CHARSET_MAC_EasternEuropean 88
-#define FX_CHARSET_MAC_Cyrillic 89
-#define FX_CHARSET_ShiftJIS 128
-#define FX_CHARSET_Korean 129
-#define FX_CHARSET_Johab 130
-#define FX_CHARSET_ChineseSimplified 134
-#define FX_CHARSET_ChineseTriditional 136
-#define FX_CHARSET_MSWin_Greek 161
-#define FX_CHARSET_MSWin_Turkish 162
-#define FX_CHARSET_MSWin_Vietnamese 163
-#define FX_CHARSET_MSWin_Hebrew 177
-#define FX_CHARSET_MSWin_Arabic 178
-#define FX_CHARSET_ArabicTraditional 179
-#define FX_CHARSET_ArabicUser 180
-#define FX_CHARSET_HebrewUser 181
-#define FX_CHARSET_MSWin_Baltic 186
-#define FX_CHARSET_MSWin_Cyrillic 204
-#define FX_CHARSET_Thai 222
-#define FX_CHARSET_MSWin_EasterEuropean 238
-#define FX_CHARSET_US 254
-#define FX_CHARSET_OEM 255
-
-#endif  // XFA_FGAS_CRT_FGAS_CODEPAGE_H_
diff --git a/xfa/fgas/font/cfgas_fontmgr.cpp b/xfa/fgas/font/cfgas_fontmgr.cpp
index 8cd799e37a..d1c4b3d580 100644
--- a/xfa/fgas/font/cfgas_fontmgr.cpp
+++ b/xfa/fgas/font/cfgas_fontmgr.cpp
@@ -10,6 +10,7 @@
 #include <memory>
 #include <utility>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_stream.h"
 #include "core/fxge/cfx_fontmapper.h"
 #include "core/fxge/cfx_fontmgr.h"
@@ -17,7 +18,6 @@
 #include "core/fxge/ifx_systemfontinfo.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/stl_util.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fgas/font/cfgas_gefont.h"
 #include "xfa/fgas/font/fgas_fontutils.h"
 
diff --git a/xfa/fgas/font/cfgas_fontmgr.h b/xfa/fgas/font/cfgas_fontmgr.h
index 8a3705335e..cca999a869 100644
--- a/xfa/fgas/font/cfgas_fontmgr.h
+++ b/xfa/fgas/font/cfgas_fontmgr.h
@@ -14,11 +14,11 @@
 #include <vector>
 
 #include "core/fxcrt/cfx_retain_ptr.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
 #include "core/fxcrt/fx_ext.h"
 #include "core/fxge/cfx_fontmapper.h"
 #include "core/fxge/fx_freetype.h"
 #include "core/fxge/ifx_systemfontinfo.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.cpp b/xfa/fgas/font/cfgas_gefont.cpp
index fdeb2ce533..ab773698e7 100644
--- a/xfa/fgas/font/cfgas_gefont.cpp
+++ b/xfa/fgas/font/cfgas_gefont.cpp
@@ -9,11 +9,11 @@
 #include <memory>
 #include <utility>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "core/fxge/cfx_substfont.h"
 #include "core/fxge/cfx_unicodeencoding.h"
 #include "core/fxge/cfx_unicodeencodingex.h"
 #include "third_party/base/ptr_util.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fgas/font/fgas_fontutils.h"
 #include "xfa/fxfa/cxfa_fontmgr.h"
 
diff --git a/xfa/fgas/font/cfgas_gefont.h b/xfa/fgas/font/cfgas_gefont.h
index 6c9f2a168d..ba2e6e69a5 100644
--- a/xfa/fgas/font/cfgas_gefont.h
+++ b/xfa/fgas/font/cfgas_gefont.h
@@ -67,8 +67,9 @@ 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<CFGAS_Stream>& pFontStream,
-                        bool bSaveStream);
+  bool LoadFontInternal(
+      const CFX_RetainPtr<CFX_SeekableStreamProxy>& pFontStream,
+      bool bSaveStream);
 #endif
   bool LoadFontInternal(CFX_Font* pExternalFont);
   bool LoadFontInternal(std::unique_ptr<CFX_Font> pInternalFont);
@@ -95,7 +96,7 @@ 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<CFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFX_SeekableStreamProxy> 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/fgas/font/fgas_fontutils.cpp b/xfa/fgas/font/fgas_fontutils.cpp
index 4dc599cd4b..f5673de56b 100644
--- a/xfa/fgas/font/fgas_fontutils.cpp
+++ b/xfa/fgas/font/fgas_fontutils.cpp
@@ -6,8 +6,8 @@
 
 #include "xfa/fgas/font/fgas_fontutils.h"
 
+#include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_ext.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fgas/font/cfgas_fontmgr.h"
 
 namespace {
diff --git a/xfa/fxfa/app/cxfa_textparser.cpp b/xfa/fxfa/app/cxfa_textparser.cpp
index 6f394dd5e2..1243f5b7ea 100644
--- a/xfa/fxfa/app/cxfa_textparser.cpp
+++ b/xfa/fxfa/app/cxfa_textparser.cpp
@@ -10,6 +10,7 @@
 #include <utility>
 #include <vector>
 
+#include "core/fxcrt/fx_codepage.h"
 #include "third_party/base/ptr_util.h"
 #include "xfa/fde/css/cfde_csscomputedstyle.h"
 #include "xfa/fde/css/cfde_cssstyleselector.h"
@@ -17,7 +18,6 @@
 #include "xfa/fde/css/fde_css.h"
 #include "xfa/fde/xml/cfde_xmlelement.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fgas/font/cfgas_fontmgr.h"
 #include "xfa/fxfa/app/cxfa_csstagprovider.h"
 #include "xfa/fxfa/app/cxfa_textparsecontext.h"
diff --git a/xfa/fxfa/app/xfa_fwltheme.cpp b/xfa/fxfa/app/xfa_fwltheme.cpp
index 629cd509e8..9af45e62df 100644
--- a/xfa/fxfa/app/xfa_fwltheme.cpp
+++ b/xfa/fxfa/app/xfa_fwltheme.cpp
@@ -6,8 +6,8 @@
 
 #include "xfa/fxfa/app/xfa_fwltheme.h"
 
+#include "core/fxcrt/fx_codepage.h"
 #include "xfa/fde/cfde_textout.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fgas/font/cfgas_gefont.h"
 #include "xfa/fwl/cfwl_barcode.h"
 #include "xfa/fwl/cfwl_caret.h"
diff --git a/xfa/fxfa/parser/cxfa_dataexporter.cpp b/xfa/fxfa/parser/cxfa_dataexporter.cpp
index 442195b1dd..c1eda8d9e6 100644
--- a/xfa/fxfa/parser/cxfa_dataexporter.cpp
+++ b/xfa/fxfa/parser/cxfa_dataexporter.cpp
@@ -9,11 +9,11 @@
 #include <vector>
 
 #include "core/fxcrt/fx_basic.h"
+#include "core/fxcrt/fx_codepage.h"
 #include "third_party/base/stl_util.h"
 #include "xfa/fde/xml/cfde_xmldoc.h"
 #include "xfa/fde/xml/cfde_xmlelement.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 #include "xfa/fxfa/parser/cxfa_widgetdata.h"
@@ -226,7 +226,8 @@ void RegenerateFormFile_Changed(CXFA_Node* pNode,
 
         CFX_RetainPtr<IFX_MemoryStream> pMemStream =
             IFX_MemoryStream::Create(true);
-        auto pTempStream = pdfium::MakeRetain<CFGAS_Stream>(pMemStream, true);
+        auto pTempStream =
+            pdfium::MakeRetain<CFX_SeekableStreamProxy>(pMemStream, true);
 
         pTempStream->SetCodePage(FX_CODEPAGE_UTF8);
         pRichTextXML->SaveXMLNode(pTempStream);
@@ -341,9 +342,10 @@ void RegenerateFormFile_Changed(CXFA_Node* pNode,
   }
 }
 
-void RegenerateFormFile_Container(CXFA_Node* pNode,
-                                  const CFX_RetainPtr<CFGAS_Stream>& pStream,
-                                  bool bSaveXML) {
+void RegenerateFormFile_Container(
+    CXFA_Node* pNode,
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream,
+    bool bSaveXML) {
   XFA_Element eType = pNode->GetElementType();
   if (eType == XFA_Element::Field || eType == XFA_Element::Draw ||
       !pNode->IsContainerNode()) {
@@ -399,7 +401,7 @@ void RegenerateFormFile_Container(CXFA_Node* pNode,
 
 void XFA_DataExporter_RegenerateFormFile(
     CXFA_Node* pNode,
-    const CFX_RetainPtr<CFGAS_Stream>& pStream,
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream,
     const char* pChecksum,
     bool bSaveXML) {
   if (pNode->IsModelNode()) {
@@ -485,15 +487,16 @@ bool CXFA_DataExporter::Export(const CFX_RetainPtr<IFX_SeekableStream>& pWrite,
   if (!pWrite)
     return false;
 
-  auto pStream = pdfium::MakeRetain<CFGAS_Stream>(pWrite, true);
+  auto pStream = pdfium::MakeRetain<CFX_SeekableStreamProxy>(pWrite, true);
   pStream->SetCodePage(FX_CODEPAGE_UTF8);
   return Export(pStream, pNode, dwFlag, pChecksum);
 }
 
-bool CXFA_DataExporter::Export(const CFX_RetainPtr<CFGAS_Stream>& pStream,
-                               CXFA_Node* pNode,
-                               uint32_t dwFlag,
-                               const char* pChecksum) {
+bool CXFA_DataExporter::Export(
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream,
+    CXFA_Node* pNode,
+    uint32_t dwFlag,
+    const char* pChecksum) {
   CFDE_XMLDoc* pXMLDoc = m_pDocument->GetXMLDoc();
   if (pNode->IsModelNode()) {
     switch (pNode->GetPacketID()) {
diff --git a/xfa/fxfa/parser/cxfa_dataexporter.h b/xfa/fxfa/parser/cxfa_dataexporter.h
index c7e5c7b70b..cd949be964 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 CFGAS_Stream;
+class CFX_SeekableStreamProxy;
 
 class CXFA_DataExporter {
  public:
@@ -26,7 +26,7 @@ class CXFA_DataExporter {
               const char* pChecksum);
 
  private:
-  bool Export(const CFX_RetainPtr<CFGAS_Stream>& pStream,
+  bool Export(const CFX_RetainPtr<CFX_SeekableStreamProxy>& 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 26dc6bd831..83c05d1269 100644
--- a/xfa/fxfa/parser/cxfa_node.cpp
+++ b/xfa/fxfa/parser/cxfa_node.cpp
@@ -13,6 +13,7 @@
 #include <vector>
 
 #include "core/fxcrt/cfx_decimal.h"
+#include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_ext.h"
 #include "fxjs/cfxjse_value.h"
 #include "third_party/base/ptr_util.h"
@@ -20,7 +21,6 @@
 #include "xfa/fde/xml/cfde_xmlelement.h"
 #include "xfa/fde/xml/cfde_xmlnode.h"
 #include "xfa/fde/xml/cfde_xmltext.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fxfa/app/xfa_ffnotify.h"
 #include "xfa/fxfa/cxfa_eventparam.h"
 #include "xfa/fxfa/cxfa_ffwidget.h"
@@ -1408,7 +1408,8 @@ void CXFA_Node::Script_NodeClass_SaveXML(CFXJSE_Arguments* pArguments) {
     }
     CFX_RetainPtr<IFX_MemoryStream> pMemoryStream =
         IFX_MemoryStream::Create(true);
-    auto pStream = pdfium::MakeRetain<CFGAS_Stream>(pMemoryStream, true);
+    auto pStream =
+        pdfium::MakeRetain<CFX_SeekableStreamProxy>(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 92196ec957..642b7641bd 100644
--- a/xfa/fxfa/parser/cxfa_simple_parser.cpp
+++ b/xfa/fxfa/parser/cxfa_simple_parser.cpp
@@ -10,6 +10,8 @@
 #include <vector>
 
 #include "core/fxcrt/cfx_checksumcontext.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.h"
+#include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/fx_ext.h"
 #include "third_party/base/ptr_util.h"
 #include "xfa/fde/xml/cfde_xmlchardata.h"
@@ -19,8 +21,6 @@
 #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/fxfa/fxfa.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
@@ -277,7 +277,7 @@ int32_t CXFA_SimpleParser::StartParse(
     XFA_XDPPACKET ePacketID) {
   CloseParser();
   m_pFileRead = pStream;
-  m_pStream = pdfium::MakeRetain<CFGAS_Stream>(pStream, false);
+  m_pStream = pdfium::MakeRetain<CFX_SeekableStreamProxy>(pStream, false);
   uint16_t wCodePage = m_pStream->GetCodePage();
   if (wCodePage != FX_CODEPAGE_UTF16LE && wCodePage != FX_CODEPAGE_UTF16BE &&
       wCodePage != FX_CODEPAGE_UTF8) {
@@ -319,7 +319,7 @@ CFDE_XMLNode* CXFA_SimpleParser::ParseXMLData(const CFX_ByteString& wsXML,
   CloseParser();
   m_pXMLDoc = pdfium::MakeUnique<CFDE_XMLDoc>();
 
-  auto pStream = pdfium::MakeRetain<CFGAS_Stream>(
+  auto pStream = pdfium::MakeRetain<CFX_SeekableStreamProxy>(
       const_cast<uint8_t*>(wsXML.raw_str()), wsXML.GetLength());
   auto pParser =
       pdfium::MakeUnique<CFDE_XMLParser>(m_pXMLDoc->GetRoot(), pStream);
diff --git a/xfa/fxfa/parser/cxfa_simple_parser.h b/xfa/fxfa/parser/cxfa_simple_parser.h
index 32b5518fab..88a7679e74 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 CFGAS_Stream;
+class CFX_SeekableStreamProxy;
 
 class CXFA_SimpleParser {
  public:
@@ -78,7 +78,7 @@ class CXFA_SimpleParser {
 
   CFDE_XMLParser* m_pXMLParser;
   std::unique_ptr<CFDE_XMLDoc> m_pXMLDoc;
-  CFX_RetainPtr<CFGAS_Stream> m_pStream;
+  CFX_RetainPtr<CFX_SeekableStreamProxy> 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 ae51c8fdc6..80f6d096ed 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/cfgas_stream.h"
+#include "core/fxcrt/cfx_seekablestreamproxy.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<CFGAS_Stream>& pStream,
+    const CFX_RetainPtr<CFX_SeekableStreamProxy>& pStream,
     const char* pChecksum = nullptr,
     bool bSaveXML = false);