Add a third_party/ copy of Python's zipfile module

dependency_manager/dependency_manager/__init__.py

 # Copyright 2015 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 os
 import sys
 
 
 CATAPULT_PATH = os.path.dirname(os.path.dirname(os.path.dirname(
     os.path.abspath(__file__))))
 CATAPULT_THIRD_PARTY_PATH = os.path.join(CATAPULT_PATH, 'third_party')
 DEPENDENCY_MANAGER_PATH = os.path.join(CATAPULT_PATH, 'dependency_manager')
 
 
 def _AddDirToPythonPath(*path_parts):
   path = os.path.abspath(os.path.join(*path_parts))
   if os.path.isdir(path) and path not in sys.path:
     sys.path.append(path)
 
 
 _AddDirToPythonPath(CATAPULT_PATH, 'common', 'py_utils')
 _AddDirToPythonPath(CATAPULT_THIRD_PARTY_PATH, 'mock')
 _AddDirToPythonPath(CATAPULT_THIRD_PARTY_PATH, 'pyfakefs')
+_AddDirToPythonPath(CATAPULT_THIRD_PARTY_PATH, 'zipfile')
 _AddDirToPythonPath(DEPENDENCY_MANAGER_PATH)
 
 
 # pylint: disable=unused-import
 from .archive_info import ArchiveInfo
 from .base_config import BaseConfig
 from .cloud_storage_info import CloudStorageInfo
 from .dependency_info import DependencyInfo
 from .exceptions import CloudStorageError
 from .exceptions import CloudStorageUploadConflictError
 from .exceptions import EmptyConfigError
 from .exceptions import FileNotFoundError
 from .exceptions import NoPathFoundError
 from .exceptions import ReadWriteError
 from .exceptions import UnsupportedConfigFormatError
 from .local_path_info import LocalPathInfo
 from .manager import DependencyManager
 # pylint: enable=unused-import