Remove all unused variables.

third_party/WebKit/Tools/Scripts/webkitpy/common/message_pool.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 228 matching lines @@
         if not self._running_inline:
             super(_Worker, self).start()
 
     def run(self):
         if not self.host:
             self.host = Host()
         if not self._running_inline:
             self._set_up_logging()
 
         worker = self._worker
-        exception_msg = ""
         _log.debug("%s starting" % self.name)
         self._running = True
 
         try:
             if hasattr(worker, 'start'):
                 worker.start()
             while self._running:
                 message = self._messages_to_worker.get()
                 if message.from_user:
                     worker.handle(message.name, message.src, *message.args)
                     self._yield_to_manager()
                 else:
                     assert message.name == 'stop', 'bad message %s' % repr(message)
                     break
 
             _log.debug("%s exiting" % self.name)
         except Queue.Empty:
             assert False, '%s: ran out of messages in worker queue.' % self.name
-        except KeyboardInterrupt as e:
+        except KeyboardInterrupt:
             self._raise(sys.exc_info())
-        except Exception as e:
+        except Exception:
             self._raise(sys.exc_info())
         finally:
             try:
                 if hasattr(worker, 'stop'):
                     worker.stop()
             finally:
                 self._post(name='done', args=(), from_user=False)
             self._close()
 
     def stop_running(self):
@@ skipping 42 matching lines @@
 
 class _WorkerLogHandler(logging.Handler):
 
     def __init__(self, worker):
         logging.Handler.__init__(self)
         self._worker = worker
         self.setLevel(worker.log_level)
 
     def emit(self, record):
         self._worker.log_messages.append(record)