Convert loose FX_Create* functions into static methods

xfa/fgas/crt/fgas_stream.cpp

 // 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/fgas_stream.h"
 
 #if _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN32_MOBILE_ || \
     _FX_OS_ == _FX_WIN64_
@@ skipping 1434 matching lines @@
   pShared->m_iTotalSize = iLength;
   pShared->m_iPosition = iStart;
   pShared->m_iStart = iStart;
   pShared->m_iLength = (dwAccess & FX_STREAMACCESS_Write) != 0 ? 0 : iLength;
   if (dwAccess & FX_STREAMACCESS_Text) {
     return IFX_Stream::CreateTextStream(pShared, true);
   }
   return pShared;
 }
 
-IFX_SeekableReadStream* FX_CreateFileRead(IFX_Stream* pBaseStream,
-                                          bool bReleaseStream) {
-  ASSERT(pBaseStream);
-  return new CFGAS_FileRead(pBaseStream, bReleaseStream);
+IFX_SeekableReadStream* IFX_Stream::MakeSeekableReadStream() {

[npm, 2016/11/30 22:58:00]

Why make here instead of Create?

[Tom Sepez, 2016/11/30 23:09:44]

Layering.  IFX_SeekableReadStream is in core/ and can't know that XFA has an
IFX_Stream.

+  return new CFGAS_FileRead(this, false);
 }
 
 CFGAS_FileRead::CFGAS_FileRead(IFX_Stream* pStream, bool bReleaseStream)
     : m_bReleaseStream(bReleaseStream), m_pStream(pStream) {
   ASSERT(m_pStream);
 }
 CFGAS_FileRead::~CFGAS_FileRead() {
   if (m_bReleaseStream) {
     m_pStream->Release();
   }
 }
 FX_FILESIZE CFGAS_FileRead::GetSize() {
   return (FX_FILESIZE)m_pStream->GetLength();
 }
 
 bool CFGAS_FileRead::ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) {
   m_pStream->Seek(FX_STREAMSEEK_Begin, (int32_t)offset);
   int32_t iLen = m_pStream->ReadData((uint8_t*)buffer, (int32_t)size);
   return iLen == (int32_t)size;
 }
 
 void CFGAS_FileRead::Release() {
   delete this;
 }