depot_tools: add infra_paths recipe module for infra-specific paths

recipe_modules/bot_update/api.py

 # Copyright 2014 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.
 
 
 """Recipe module to ensure a checkout is consistant on a bot."""
 
 from recipe_engine import recipe_api
 
 
@@ skipping 103 matching lines @@
 
     # The gerrit_ref and gerrit_repo must be together or not at all.  If one is
     # missing, clear both of them.
     if not gerrit_ref or not gerrit_repo:
       gerrit_repo = gerrit_ref = None
     assert (gerrit_ref != None) == (gerrit_repo != None)
 
     # Point to the oauth2 auth files if specified.
     # These paths are where the bots put their credential files.
     if patch_oauth2:
-      email_file = self.m.path['build'].join(
+      email_file = self.m.infra_paths['build'].join(
           'site_config', '.rietveld_client_email')
-      key_file = self.m.path['build'].join(
+      key_file = self.m.infra_paths['build'].join(
           'site_config', '.rietveld_secret_key')
     else:
       email_file = key_file = None
 
     rev_map = cfg.got_revision_mapping.as_jsonish()
 
     flags = [
         # 1. Do we want to run? (master/builder/slave).
         ['--master', master],
         ['--builder', builder],
@@ skipping 128 matching lines @@
         else:
           # This is actual patch failure.
           self.m.tryserver.set_patch_failure_tryjob_result()
           self.m.python.failing_step(
               'Patch failure', 'Check the bot_update step for details')
 
       # bot_update actually just sets root to be the folder name of the
       # first solution.
       if step_result.json.output['did_run']:
         co_root = step_result.json.output['root']
-        cwd = kwargs.get('cwd', self.m.path['slave_build'])
+        cwd = kwargs.get('cwd', self.m.infra_paths['slave_build'])
         if 'checkout' not in self.m.path:
           self.m.path['checkout'] = cwd.join(*co_root.split(self.m.path.sep))
 
     return step_result