Fix webkit-patch --help.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/help_command.py

 # Copyright (c) 2016 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 18 matching lines @@
 import optparse
 
 from webkitpy.tool.commands.command import Command
 
 
 class HelpCommand(Command):
     name = "help"
     help_text = "Display information about this program or its subcommands"
     argument_names = "[COMMAND]"
 
-    def __init__(self):
+    def __init__(self, tool=None):
         options = [
             optparse.make_option(
                 "-a",
                 "--all-commands",
                 action="store_true",
                 dest="show_all_commands",
                 help="Print all available commands"),
         ]
         super(HelpCommand, self).__init__(options)
-        # A hack used to pass --all-commands to _help_epilog even though it's called by the OptionParser.
+        # A hack used to pass --all-commands to help_epilog even though it's called by the OptionParser.
         self.show_all_commands = False
-        self._tool = None
+        # self._tool is used in help_epilog, so it's passed in the initializer rather than set in the execute method.
+        self._tool = tool
 
-    def _help_epilog(self):
+    def help_epilog(self):
         # Only show commands which are relevant to this checkout's SCM system.  Might this be confusing to some users?
         if self.show_all_commands:
             epilog = "All %prog commands:\n"
             relevant_commands = self._tool.commands[:]
         else:
             epilog = "Common %prog commands:\n"
             relevant_commands = filter(self._tool.should_show_in_main_help, self._tool.commands)
         longest_name_length = max(len(command.name) for command in relevant_commands)
         relevant_commands.sort(lambda a, b: cmp(a.name, b.name))
         command_help_texts = ["   %s   %s\n" % (command.name.ljust(longest_name_length), command.help_text)
                               for command in relevant_commands]
         epilog += "%s\n" % "".join(command_help_texts)
         epilog += "See '%prog help --all-commands' to list all commands.\n"
         epilog += "See '%prog help COMMAND' for more information on a specific command.\n"
         return epilog.replace("%prog", self._tool.name())  # Use of %prog here mimics OptionParser.expand_prog_name().
 
     # FIXME: This is a hack so that we don't show --all-commands as a global option:
     def _remove_help_options(self):
         for option in self.options:
             self.option_parser.remove_option(option.get_opt_string())
 
     def execute(self, options, args, tool):
-        self._tool = tool
         if args:
             command = self._tool.command_by_name(args[0])
             if command:
                 print command.standalone_help()
                 return 0
 
         self.show_all_commands = options.show_all_commands
         self._remove_help_options()
         self.option_parser.print_help()
         return 0