Convert loose FX_Create* functions into static methods

xfa/fgas/font/cfgas_fontmgr.cpp

 // Copyright 2015 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/font/cfgas_fontmgr.h"
 
 #include <memory>
 #include <utility>
@@ skipping 891 matching lines @@
   if (!hFont)
     return nullptr;
 
   uint32_t dwFileSize = pSystemFontInfo->GetFontData(hFont, 0, nullptr, 0);
   if (dwFileSize == 0)
     return nullptr;
 
   uint8_t* pBuffer = FX_Alloc(uint8_t, dwFileSize + 1);
   dwFileSize = pSystemFontInfo->GetFontData(hFont, 0, pBuffer, dwFileSize);
 
-  return FX_CreateMemoryStream(pBuffer, dwFileSize, true);
+  return IFX_MemoryStream::Create(pBuffer, dwFileSize, true);
 }
 
 IFX_SeekableReadStream* CFGAS_FontMgr::CreateFontStream(
     const CFX_ByteString& bsFaceName) {
   CFX_FontMgr* pFontMgr = CFX_GEModule::Get()->GetFontMgr();
   CFX_FontMapper* pFontMapper = pFontMgr->GetBuiltinMapper();
 
   if (!pFontMapper)
     return nullptr;
 
@@ skipping 284 matching lines @@
 }
 
 int32_t CFGAS_FontMgr::IsPartName(const CFX_WideString& Name1,
                                   const CFX_WideString& Name2) {
   if (Name1.Find(Name2.c_str()) != -1)
     return 1;
   return 0;
 }
 
 #endif  // _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_