[Cronet] run pylint in Cronet presubmit check

components/cronet/tools/extract_from_jars.py

 #!/usr/bin/env python
 #
 # 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 fnmatch
 import optparse
 import os
 import sys
 
 REPOSITORY_ROOT = os.path.abspath(os.path.join(
     os.path.dirname(__file__), '..', '..', '..'))
 
 sys.path.append(os.path.join(REPOSITORY_ROOT, 'build/android/gyp/util'))
 import build_utils
 
@@ skipping 26 matching lines @@
     build_utils.WriteDepfile(options.depfile,
                              build_utils.GetPythonDependencies())
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
 
 if __name__ == '__main__':
   sys.exit(main())