Update PRESUBMIT.py to be more in sync with Blink CQ

BUG=317931
R=dpranke@chromium.org

Review URL: https://codereview.chromium.org/181233010

git-svn-id: svn://svn.chromium.org/blink/trunk@168529 bbb929c8-8fbe-4397-9dbb-9b2b20218538