XFA: Add missing libtiff file from commit 9c2c87d1c744.

third_party/third_party.gyp

 # 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.
 
 {
   'variables': {
     'pdf_enable_xfa%': 0,  # Set to 1 by standalone.gypi in standalone builds.
   },
   'target_defaults': {
     'defines': [
@@ skipping 312 matching lines @@
     },
   ],
   'conditions': [
     ['pdf_enable_xfa==1', {
       'targets': [
         {
           'target_name': 'fx_tiff',
           'type': 'static_library',
           'sources': [
             'libtiff/tiffiop.h',
+            'libtiff/tiffvers.h',
             'libtiff/tif_aux.c',
             'libtiff/tif_close.c',
             'libtiff/tif_codec.c',
             'libtiff/tif_color.c',
             'libtiff/tif_compress.c',
             'libtiff/tif_dir.c',
             'libtiff/tif_dirinfo.c',
             'libtiff/tif_dirread.c',
             'libtiff/tif_dirwrite.c',
             'libtiff/tif_dumpmode.c',
@@ skipping 21 matching lines @@
             'libtiff/tif_version.c',
             'libtiff/tif_warning.c',
             'libtiff/tif_write.c',
             'libtiff/tif_zip.c',
           ],
         },
       ],
     }],
   ],
 }