Add jpeg_skip_scanlines() API to libjpeg-turbo

jpeglib.h

 /*
  * jpeglib.h
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1998, Thomas G. Lane.
  * Modified 2002-2009 by Guido Vollbeding.
  * Modifications:
  * Copyright (C) 2009-2011, 2013, D. R. Commander.
+ * Copyright (C) 2015, Google, Inc.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file defines the application interface for the JPEG library.
  * Most applications using the library need only include this file,
  * and perhaps jerror.h if they want to know the exact error codes.
  */
 
 #ifndef JPEGLIB_H
 #define JPEGLIB_H
 
@@ skipping 1063 matching lines @@
  * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
  * JPEG_SUSPENDED is only possible if you use a data source module that can
  * give a suspension return (the stdio source module doesn't).
  */
 
 /* Main entry points for decompression */
 EXTERN(boolean) jpeg_start_decompress JPP((j_decompress_ptr cinfo));
 EXTERN(JDIMENSION) jpeg_read_scanlines JPP((j_decompress_ptr cinfo,
                                             JSAMPARRAY scanlines,
                                             JDIMENSION max_lines));
+EXTERN(JDIMENSION) jpeg_skip_scanlines (j_decompress_ptr cinfo,
+                                        JDIMENSION num_lines);
 EXTERN(boolean) jpeg_finish_decompress JPP((j_decompress_ptr cinfo));
 
 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
 EXTERN(JDIMENSION) jpeg_read_raw_data JPP((j_decompress_ptr cinfo,
                                            JSAMPIMAGE data,
                                            JDIMENSION max_lines));
 
 /* Additional entry points for buffered-image mode. */
 EXTERN(boolean) jpeg_has_multiple_scans JPP((j_decompress_ptr cinfo));
 EXTERN(boolean) jpeg_start_output JPP((j_decompress_ptr cinfo,
@@ skipping 107 matching lines @@
 #include "jerror.h"             /* fetch error codes too */
 #endif
 
 #ifdef __cplusplus
 #ifndef DONT_USE_EXTERN_C
 }
 #endif
 #endif
 
 #endif /* JPEGLIB_H */