Fix pylint unused-* warnings in webkitpy/tool.

third_party/WebKit/Tools/Scripts/webkitpy/tool/multicommandtool.py

 # Copyright (c) 2009 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 96 matching lines @@
 
     def path(self):
         raise NotImplementedError("subclasses must implement")
 
     def command_completed(self):
         pass
 
     def should_show_in_main_help(self, command):
         return command.show_in_main_help
 
-    def should_execute_command(self, command):
+    def should_execute_command(self, command):  # Argument may be used in subclasses - pylint: disable=unused-argument
         return True
 
     def _add_global_options(self, option_parser):
         global_options = self.global_options or []
         for option in global_options:
             option_parser.add_option(option)
 
     def handle_global_options(self, options):
         pass
 
@@ skipping 18 matching lines @@
 
         while True:
             try:
                 result = command.check_arguments_and_execute(options, args, self)
                 break
             except TryAgain as e:
                 pass
 
         self.command_completed()
         return result