Remove CFX_MapPtrToPtr and templates.

core/fxcrt/fx_basic_plex.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 "core/fxcrt/fx_memory.h"
-#include "core/fxcrt/plex.h"
-
-CFX_Plex* CFX_Plex::Create(CFX_Plex*& pHead,
-                           uint32_t nMax,
-                           uint32_t cbElement) {
-  CFX_Plex* p =
-      (CFX_Plex*)FX_Alloc(uint8_t, sizeof(CFX_Plex) + nMax * cbElement);
-  p->pNext = pHead;
-  pHead = p;
-  return p;
-}
-void CFX_Plex::FreeDataChain() {
-  CFX_Plex* p = this;
-  while (p) {
-    CFX_Plex* old = p;
-    p = p->pNext;
-    FX_Free(old);
-  }
-}