Update comments for net/data/verify_certificate_chain_unittest/

net/data/verify_certificate_chain_unittest/unknown-non-critical-policy-qualifier/generate-chains.py

 #!/usr/bin/python
 # Copyright (c) 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.
 
-"""The intermediate has a policies extension (not marked as critical),
-which contains an unknown qualifer (1.2.3.4)."""
+"""Certificate chain where the intermediate has a policies extension (not
+marked as critical) which contains an unknown policy qualifer (1.2.3.4)."""
 
 import sys
 sys.path += ['..']
 
 import common
 
-# Self-signed root certificate (used as trust anchor).
+# Self-signed root certificate.
 root = common.create_self_signed_root_certificate('Root')
 
 # Intermediate that has a non-critical policies extension containing an unknown
 # policy qualifer.
 intermediate = common.create_intermediate_certificate('Intermediate', root)
 intermediate.get_extensions().add_property(
     '2.5.29.32', ('DER:30:13:30:11:06:02:2a:03:30:0b:30:09:06:03:'
                   '2a:03:04:0c:02:68:69'))
 
 # Target certificate.
 target = common.create_end_entity_certificate('Target', intermediate)
 
 chain = [target, intermediate, root]
 common.write_chain(__doc__, chain, 'chain.pem')