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

chrome/test/mini_installer/cleaner_visitor.py

+# Copyright 2017 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 _winreg
+import os
+import shutil
+
+class CleanerVisitor(object):
+
+  def VisitFile(self, entry):
+    """ Delete the file if file is existed but shouldn't exist. Only support
+        Directory.
+    """
+    if entry.is_file_existed and not entry.should_file_exist and os.path.isdir(
+        entry.file_path):
+      shutil.rmtree(entry.file_path, ignore_errors=True)
+
+  def VisitRegistryKey(self, entry):
+    """ Reset the registry key to match the expectation.
+    """
+    if entry.key_handle is not None and entry.should_key_exist == 'forbidden':
+      try:
+        self._DeleteRegKey(entry.root_key_value, entry.sub_key)
+      except WindowsError:
+        # Suppress any delete error
+        pass
+
+
+  def VisitRegistryValue(self, entry):
+    pass
+
+  def VisitProcess(self, entry):
+    pass
+
+  def _DeleteRegKey(self, root, key_path):
+    """ Delete a registry key recursively.
+
+        Args:
+          root: An integer represents HKEY_ constant.
+          key_path: A string represents the path of key that needs to be
+                    deleted.
+    """
+    with _winreg.OpenKey(root, key_path, 0, _winreg.KEY_SET_VALUE |
+                                            _winreg.KEY_READ |
+                                            _winreg.KEY_WOW64_32KEY) as key:
+      num_of_sub_keys, _, _ =  _winreg.QueryInfoKey(key)
+      for i in range(0, num_of_sub_keys):
+        self._DeleteRegKey(root, key_path + "\\" + _winreg.EnumKey(key, i))
+    _winreg.DeleteKey(root, key_path)