Cleanup machine based on the state in configuration file for mini installer test.

chrome/test/mini_installer/variable_expander.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import base64
 import hashlib
 import os
 import string
 import win32api
 import win32com.client
@@ skipping 146 matching lines @@
           'CHROME_SHORT_NAME': 'Chromium',
           'CHROME_UPDATE_REGISTRY_SUBKEY': 'Software\\Chromium',
           'CHROME_CLIENT_STATE_KEY': 'Software\\Chromium',
           'SUPPORTS_SXS': False
       })
     else:
       raise KeyError("Unknown mini_installer product name '%s'" %
                      mini_installer_product_name)
 
 
-  def Expand(self, str):
+  def Expand(self, input_string):
     """Expands variables in the given string.
 
     This method resolves only variables defined in the constructor. It does not
     resolve environment variables. Any dollar signs that are not part of
     variables must be escaped with $$, otherwise a KeyError or a ValueError will
     be raised.
 
     Args:
-      str: A string.
+      input_string: A string with variables.
 
     Returns:
       A new string created by replacing variables with their values.
     """
-    return string.Template(str).substitute(self._variable_mapping)
+    return string.Template(input_string).substitute(self._variable_mapping)