checklicenses: Add a suppression for third_party/pdfium.

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 optparse
 import os.path
@@ skipping 242 matching lines @@
     ],
     'third_party/molokocacao': [  # http://crbug.com/98453
         'UNKNOWN',
     ],
     'third_party/npapi/npspy': [
         'UNKNOWN',
     ],
     'third_party/ocmock/OCMock': [  # http://crbug.com/98454
         'UNKNOWN',
     ],
+    'third_party/pdfium': [  # http://crbug.com/374943
+        'UNKNOWN',
+    ],
     'third_party/ply/__init__.py': [
         'UNKNOWN',
     ],
     'third_party/protobuf': [  # http://crbug.com/98455
         'UNKNOWN',
     ],
 
     # http://crbug.com/222831
     # https://bitbucket.org/eliben/pyelftools/issue/12
     'third_party/pyelftools': [
@@ skipping 221 matching lines @@
   option_parser.add_option('--ignore-suppressions',
                            action='store_true',
                            default=False,
                            help='Ignore path-specific license whitelist.')
   options, args = option_parser.parse_args()
   return check_licenses(options, args)
 
 
 if '__main__' == __name__:
   sys.exit(main())