Use virtualenv to run commit_queue script

third_party/cq_client/validate_config.py

 #!/usr/bin/env python
 # 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.
 
 """CQ config validation library."""
 
 import argparse
-# The 'from google import protobuf' below was replaced to fix an issue where
-# some users may have built-in google package installed on their system, which
-# is incompatible with cq_pb2 below. This hack can be removed after
-# http://crbug.com/503067 is resolved.
-import protobuf26 as protobuf
+from google import protobuf
 import logging
 import re
 import sys
 
 from cq_client import cq_pb2
 
 
 REQUIRED_FIELDS = [
   'version',
   'rietveld',
@@ skipping 79 matching lines @@
     try:
       re.compile(base)
     except re.error:
       logging.error('failed to parse "%s" in project_bases as a regexp', base)
       return False
 
   # TODO(sergiyb): For each field, check valid values depending on its
   # semantics, e.g. email addresses, regular expressions etc.
 
   return True