Fixup incorrect include guards.

xfa/src/fgas/include/fx_mem.h

 // 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 _FX_MEMORY
-#define _FX_MEMORY
+#ifndef XFA_SRC_FGAS_INCLUDE_FX_MEM_H_
+#define XFA_SRC_FGAS_INCLUDE_FX_MEM_H_
 
 #include "core/include/fxcrt/fx_memory.h"  // For FX_Alloc().
 
 class IFX_MEMAllocator;
 class CFX_Target;
 enum FX_ALLOCTYPE {
   FX_ALLOCTYPE_Default = 0,
   FX_ALLOCTYPE_Static,
   FX_ALLOCTYPE_Fixed,
   FX_ALLOCTYPE_Dynamic,
@@ skipping 27 matching lines @@
   }
   void* operator new(size_t size, void* place) { return place; }
   void operator delete(void* p, void* place) {}
 };
 #define FXTARGET_NewWith(__allocator__) new (__allocator__)
 #define FXTARGET_DeleteWith(__class__, __allocator__, pointer) \
   {                                                            \
     (pointer)->~__class__();                                   \
     (pointer)->operator delete((pointer), (__allocator__));    \
   }
-#endif
+
+#endif  // XFA_SRC_FGAS_INCLUDE_FX_MEM_H_