Upgrade liblouis to 2.6.0.

tools/checklicenses/checklicenses.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Makes sure that all files contain proper licensing information."""
 
 
 import json
 import optparse
@@ skipping 213 matching lines @@
     ],
     'third_party/libevent': [  # http://crbug.com/98309
         'UNKNOWN',
     ],
     'third_party/libjingle/source/talk': [  # http://crbug.com/98310
         'UNKNOWN',
     ],
     'third_party/libjpeg_turbo': [  # http://crbug.com/98314
         'UNKNOWN',
     ],
+
+    # Many liblouis files are mirrored but not used in the NaCl module.
+    # They are not excluded from the mirror because of lack of infrastructure
+    # support.  Getting license headers added to the files where missing is
+    # tracked in https://github.com/liblouis/liblouis/issues/22.
+    'third_party/liblouis/src': [
+        'GPL (v3 or later)',
+        'UNKNOWN',
+    ],
+
     'third_party/libpng': [  # http://crbug.com/98318
         'UNKNOWN',
     ],
 
     # The following files lack license headers, but are trivial.
     'third_party/libusb/src/libusb/os/poll_posix.h': [
         'UNKNOWN',
     ],
 
     'third_party/libvpx/source': [  # http://crbug.com/98319
@@ skipping 282 matching lines @@
                            action='store_true',
                            default=False,
                            help='Ignore path-specific license whitelist.')
   option_parser.add_option('--json', help='Path to JSON output file')
   options, args = option_parser.parse_args()
   return check_licenses(options, args)
 
 
 if '__main__' == __name__:
   sys.exit(main())