git: use new python script to bootstrap git on windows

recipe_modules/git/api.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 itertools
 import re
 
 from recipe_engine import recipe_api
 
 class GitApi(recipe_api.RecipeApi):
@@ skipping 23 matching lines @@
     except self.m.step.StepFailure as f:
       if can_fail_build:
         raise
       else:
         return f.result
 
   def ensure_win_git_tooling(self):
     """Ensures that depot_tools/git.bat actually exists."""
     if not self.m.platform.is_win or self.initialized_win_git:
       return
-    self.m.step(
+    self.m.python(
         'ensure git tooling on windows',
-        [self.package_repo_resource('bootstrap', 'win', 'win_tools.bat')],
+        self.package_repo_resource('bootstrap', 'win', 'git_bootstrap.py'),
+        ['--verbose'],
         infra_step=True,
         cwd=self.package_repo_resource(),
         timeout=300)
     self.initialized_win_git = True
 
   def fetch_tags(self, remote_name=None, **kwargs):
     """Fetches all tags from the remote."""
     kwargs.setdefault('name', 'git fetch tags')
     remote_name = remote_name or 'origin'
     return self('fetch', remote_name, '--tags', **kwargs)
@@ skipping 344 matching lines @@
 
     Args:
       bundle_path (Path): The path of the output bundle.
       refs (list): The list of refs to include in the bundle. If None, all
           refs in the Git checkout will be bundled.
       kwargs: Forwarded to '__call__'.
     """
     if not rev_list_args:
       rev_list_args = ['--all']
     self('bundle', 'create', bundle_path, *rev_list_args, **kwargs)