Update comments for net/data/verify_certificate_chain_unittest/

net/data/verify_certificate_chain_unittest/basic-constraints-pathlen-0-self-issued/generate-chains.py

Index: net/data/verify_certificate_chain_unittest/basic-constraints-pathlen-0-self-issued/generate-chains.py
diff --git a/net/data/verify_certificate_chain_unittest/basic-constraints-pathlen-0-self-issued/generate-chains.py b/net/data/verify_certificate_chain_unittest/basic-constraints-pathlen-0-self-issued/generate-chains.py
index 46b6b843f7899b0ffff207fa1250540a9841f96c..059620a22ee024a9fdd9f28865198c624f96b76d 100755
--- a/net/data/verify_certificate_chain_unittest/basic-constraints-pathlen-0-self-issued/generate-chains.py
+++ b/net/data/verify_certificate_chain_unittest/basic-constraints-pathlen-0-self-issued/generate-chains.py
@@ -3,16 +3,15 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-"""Certificate chain with 2 intermediates. The first intermediate has a basic
-constraints path length of 0. The second one is self-issued so does not count
-against the path length."""
+"""Certificate chain where the intermediate sets pathlen=0, and is followed by
+a self-issued intermediate."""
 
 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 with pathlen 0