CrOS: Load Chromite pins from JSON.

PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 """Top-level presubmit script for buildbot.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
@@ skipping 94 matching lines @@
       join('scripts', 'slave', 'recipe_modules', '*', 'tests'))
   for path in recipe_modules_tests:
     tests.extend(input_api.canned_checks.GetUnitTestsInDirectory(
         input_api,
         output_api,
         path,
         whitelist))
 
   try:
     sys.path = infra_path + sys.path
-    import master_cfg_utils  # pylint: disable=F0401
+    import common.master_cfg_utils  # pylint: disable=F0401
     # Run the tests.
-    with master_cfg_utils.TemporaryMasterPasswords():
+    with common.master_cfg_utils.TemporaryMasterPasswords():
       output = input_api.RunTests(tests)
 
     output.extend(input_api.canned_checks.PanProjectChecks(
       input_api, output_api, excluded_paths=black_list))
     return output
   finally:
     sys.path = sys_path_backup
 
 
 def ConditionalChecks(input_api, output_api):
@@ skipping 35 matching lines @@
   output.extend(BuildInternalCheck(output, input_api, output_api))
   return output
 
 
 def CheckChangeOnCommit(input_api, output_api):
   output = CommonChecks(input_api, output_api)
   output.extend(ConditionalChecks(input_api, output_api))
   output.extend(CommitChecks(input_api, output_api))
   output.extend(BuildInternalCheck(output, input_api, output_api))
   return output