Remove all unused variables.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/server_base.py

 # Copyright (C) 2011 Google 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
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 140 matching lines @@
 
     def _remove_stale_logs(self):
         """This routine can be overridden by subclasses to try and remove logs
         left over from a prior run. This routine should log warnings if the
         files cannot be deleted, but should not fail unless failure to
         delete the logs will actually cause start() to fail."""
         # Sometimes logs are open in other processes but they should clear eventually.
         for log_prefix in self._log_prefixes:
             try:
                 self._remove_log_files(self._output_dir, log_prefix)
-            except OSError as e:
+            except OSError:
                 _log.warning('Failed to remove old %s %s files' % (self._name, log_prefix))
 
     def _spawn_process(self):
         _log.debug('Starting %s server, cmd="%s"' % (self._name, self._start_cmd))
         self._process = self._executive.popen(self._start_cmd,
                                               env=self._env,
                                               cwd=self._cwd,
                                               stdout=self._stdout,
                                               stderr=self._stderr)
         pid = self._process.pid
         self._filesystem.write_text_file(self._pid_file, str(pid))
         return pid
 
     def _stop_running_server(self):
         self._wait_for_action(self._check_and_kill)
         if self._filesystem.exists(self._pid_file):
             self._filesystem.remove(self._pid_file)
 
     def _check_and_kill(self):
         if self._executive.check_running_pid(self._pid):
             _log.debug('pid %d is running, killing it' % self._pid)
-            host = self._port_obj.host
             self._executive.kill_process(self._pid)
             return False
         else:
             _log.debug('pid %d is not running' % self._pid)
 
         return True
 
     def _remove_pid_file(self):
         if self._filesystem.exists(self._pid_file):
             self._filesystem.remove(self._pid_file)
@@ skipping 80 matching lines @@
             except IOError as e:
                 if e.errno in (errno.EALREADY, errno.EADDRINUSE):
                     raise ServerError('Port %d is already in use.' % port)
                 elif self._platform.is_win() and e.errno in (errno.WSAEACCES,):  # pylint: disable=E1101
                     raise ServerError('Port %d is already in use.' % port)
                 else:
                     raise
             finally:
                 s.close()
         _log.debug('all ports are available')