Extract functions from path recipe module so that step can depend on it

scripts/slave/recipe_modules/git_clone_bundler/api.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 hashlib
 
 from slave import recipe_api
 
 """
 The 'git_clone_bundler' creates and uploads 'clone.bundle' packages to
@@ skipping 12 matching lines @@
 
   @property
   def bundle_dir(self):
     return self.base_path.join('bundles')
 
   @staticmethod
   def _hashname(base):
     return hashlib.md5(base).hexdigest()
 
   def _setup(self):
-    self.m.path.rmtree('old bundles', self.bundle_dir)
-    self.m.path.makedirs('bundles', self.bundle_dir)
+    self.m.file.rmtree('old bundles', self.bundle_dir)
+    self.m.file.makedirs('bundles', self.bundle_dir)
 
   def _bundle(self, git_path, gs_bucket, gs_subpath, refs, name,
               unauthenticated_url):
     """
     Creates a Git bundle from a Git repository and uploads it to Google Storage.
 
     Args:
       git_path: (Path) The path of the Git repository to bundle.
       gs_bucket: (str) The name of the Google Storage bucket.
       gs_subpath: (str) The path within the Google Storage bucket.
@@ skipping 75 matching lines @@
         that repository's bundle was uploaded.
     """
     self._setup()
 
     # Checkout the repository.
     checkout_root = self.base_path.join(
         'repo',
         hashlib.md5(repo_manifest_url).hexdigest())
 
     # Initialize the 'repo' checkout.
-    self.m.path.makedirs('repo', checkout_root)
+    self.m.file.makedirs('repo', checkout_root)
     self.m.repo.init(repo_manifest_url, cwd=checkout_root)
     self.m.repo.sync('--no-clone-bundle', cwd=checkout_root)
 
     # The repository list produces absolute paths, so we want to convert our
     # 'checkout_root' to an absolute path for relative path calculation.
     abs_checkout_root = self.m.path.abspath(checkout_root)
     errors = []
     bundle_map = {}
     visited = set()
     for path, name in self.m.repo.list(cwd=checkout_root):
@@ skipping 17 matching lines @@
       except self.m.step.StepFailure as e:
         result = self.m.step.active_result
         result.presentation.step_text = 'Exception: %s' % (e,)
         result.presentation.status = self.m.step.FAILURE
         errors.append(e)
 
     if errors:
       raise self.m.step.StepFailure("Encountered %d bundler failure(s)" % (
           len(errors,)))
     return bundle_map