Remove all unused variables.

third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/scm/git.py

 # Copyright (c) 2009, 2010, 2011 Google Inc. All rights reserved.
 # Copyright (c) 2009 Apple Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 54 matching lines @@
         if 'cwd' not in full_kwargs:
             full_kwargs['cwd'] = self.checkout_root
         return self._run(full_command_args, **full_kwargs)
 
     @classmethod
     def in_working_directory(cls, path, executive=None):
         try:
             executive = executive or Executive()
             return executive.run_command([cls.executable_name, 'rev-parse', '--is-inside-work-tree'],
                                          cwd=path, error_handler=Executive.ignore_error).rstrip() == "true"
-        except OSError as e:
+        except OSError:
             # The Windows bots seem to through a WindowsError when git isn't installed.
             return False
 
     def find_checkout_root(self, path):
         # "git rev-parse --show-cdup" would be another way to get to the root
         checkout_root = self._run_git(['rev-parse', '--show-toplevel'], cwd=(path or "./")).strip()
         if not self._filesystem.isabs(checkout_root):  # Sometimes git returns relative paths
             checkout_root = self._filesystem.join(path, checkout_root)
         return checkout_root
 
@@ skipping 240 matching lines @@
             return False
         return True
 
     def ensure_cleanly_tracking_remote_master(self):
         self._discard_working_directory_changes()
         self._run_git(['checkout', '-q', self._branch_tracking_remote_master()])
         self._discard_local_commits()
 
     def get_issue_number(self):
         return str(self._run_git(['cl', 'issue']).split()[2])