Get rid of the use_glib gn variable.

mojo/tools/mopy/gn_unittest.py

 # Copyright 2014 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.
 
 import itertools
 import sys
 import unittest
 
 import mopy.gn as gn
 
@@ skipping 41 matching lines @@
       "is_asan": [False, True],
       "use_goma": [False],
       "mojo_use_nacl": [False, True],
       "mojo_use_go": [False],
       "dcheck_always_on": [False, True],
     }
 
     for args in _iterate_over_config(configs_to_test):
       if args.get("target_os", None) is None and sys.platform[:5] == "linux":
         args["use_aura"] = False
-        args["use_glib"] = False
       config = gn.ConfigForGNArgs(args)
       new_args = gn.GNArgsForConfig(config)
       self.assertDictEqual(args, new_args)
 
 
 def _iterate_over_config(config):
   def product_to_dict(p):
     return dict(filter(lambda x: x[1] is not None, zip(config.keys(), p)))
   return itertools.imap(product_to_dict, itertools.product(*config.values()))
 
 
 if __name__ == "__main__":
   unittest.main()