Reland of PyLint fixes for tools-webrtc and webrtc/tools

tools-webrtc/gn_check_autofix.py

 #!/usr/bin/env python
 
 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
@@ skipping 25 matching lines @@
 
 class TemporaryDirectory(object):
   def __init__(self):
     self._closed = False
     self._name = None
     self._name = tempfile.mkdtemp()
 
   def __enter__(self):
     return self._name
 
-  def __exit__(self, exc, value, tb):
+  def __exit__(self, exc, value, _tb):
     if self._name and not self._closed:
       shutil.rmtree(self._name)
       self._closed = True
 
 
 def Run(cmd):
   print 'Running:', ' '.join(cmd)
   sub = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
   return sub.communicate()
 
@@ skipping 92 matching lines @@
       print '\n'.join(error)
       continue
 
   for path, missing_deps in errors_by_file.items():
     FixErrors(path, missing_deps, deleted_sources)
 
   return 0
 
 if __name__ == '__main__':
   sys.exit(main())