Simplify PDFium by removing code that's not used in the open source repo.

core/src/fxcodec/libjpeg/jmemsys.h

 /*
  * jmemsys.h
  *
  * Copyright (C) 1992-1997, Thomas G. Lane.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This include file defines the interface between the system-independent
  * and system-dependent portions of the JPEG memory manager.  No other
  * modules need include it.  (The system-independent portion is jmemmgr.c;
  * there are several different versions of the system-dependent portion.)
  *
  * This file works as-is for the system-dependent memory managers supplied
  * in the IJG distribution.  You may need to modify it if you write a
- * custom memory manager.  If system-dependent changes are needed in
- * this file, the best method is to #ifdef them based on a configuration
- * symbol supplied in jconfig.h, as we have done with USE_MSDOS_MEMMGR
- * and USE_MAC_MEMMGR.
+ * custom memory manager.
  */
 
 
 /* Short forms of external names for systems with brain-damaged linkers. */
 
 #ifdef NEED_SHORT_EXTERNAL_NAMES
 #define jpeg_get_small          jGetSmall
 #define jpeg_free_small         jFreeSmall
 #define jpeg_get_large          jGetLarge
 #define jpeg_free_large         jFreeLarge
@@ skipping 79 matching lines @@
 
 /*
  * This structure holds whatever state is needed to access a single
  * backing-store object.  The read/write/close method pointers are called
  * by jmemmgr.c to manipulate the backing-store object; all other fields
  * are private to the system-dependent backing store routines.
  */
 
 #define TEMP_NAME_LENGTH   64   /* max length of a temporary file's name */
 
-
-#ifdef USE_MSDOS_MEMMGR         /* DOS-specific junk */
-
-typedef unsigned short XMSH;    /* type of extended-memory handles */
-typedef unsigned short EMSH;    /* type of expanded-memory handles */
-
-typedef union {
-  short file_handle;            /* DOS file handle if it's a temp file */
-  XMSH xms_handle;              /* handle if it's a chunk of XMS */
-  EMSH ems_handle;              /* handle if it's a chunk of EMS */
-} handle_union;
-
-#endif /* USE_MSDOS_MEMMGR */
-
-#ifdef USE_MAC_MEMMGR           /* Mac-specific junk */
-#include <Files.h>
-#endif /* USE_MAC_MEMMGR */
-
-
 typedef struct backing_store_struct * backing_store_ptr;
 
 typedef struct backing_store_struct {
   /* Methods for reading/writing/closing this backing-store object */
   JMETHOD(void, read_backing_store, (j_common_ptr cinfo,
                                      backing_store_ptr info,
                                      void FAR * buffer_address,
                                      long file_offset, long byte_count));
   JMETHOD(void, write_backing_store, (j_common_ptr cinfo,
                                       backing_store_ptr info,
                                       void FAR * buffer_address,
                                       long file_offset, long byte_count));
   JMETHOD(void, close_backing_store, (j_common_ptr cinfo,
                                       backing_store_ptr info));
 
   /* Private fields for system-dependent backing-store management */
-#ifdef USE_MSDOS_MEMMGR
-  /* For the MS-DOS manager (jmemdos.c), we need: */
-  handle_union handle;          /* reference to backing-store storage object */
-  char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
-#else
-#ifdef USE_MAC_MEMMGR
-  /* For the Mac manager (jmemmac.c), we need: */
-  short temp_file;              /* file reference number to temp file */
-  FSSpec tempSpec;              /* the FSSpec for the temp file */
-  char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
-#else
   /* For a typical implementation with temp files, we need: */
-#ifndef _FPDFAPI_MINI_
   FXSYS_FILE * temp_file;               /* stdio reference to temp file */
   char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */
-#endif
-#endif
-#endif
 } backing_store_info;
 
 
 /*
  * Initial opening of a backing-store object.  This must fill in the
  * read/write/close pointers in the object.  The read/write routines
  * may take an error exit if the specified maximum file size is exceeded.
  * (If jpeg_mem_available always returns a large value, this routine can
  * just take an error exit.)
  */
@@ skipping 10 matching lines @@
  * manager pointer).  It should return a suitable default value for
  * max_memory_to_use; this may subsequently be overridden by the surrounding
  * application.  (Note that max_memory_to_use is only important if
  * jpeg_mem_available chooses to consult it ... no one else will.)
  * jpeg_mem_term may assume that all requested memory has been freed and that
  * all opened backing-store objects have been closed.
  */
 
 EXTERN(long) jpeg_mem_init JPP((j_common_ptr cinfo));
 EXTERN(void) jpeg_mem_term JPP((j_common_ptr cinfo));