[DevTools] Fix line number in messages from inline scripts with source url

R=vsevik@chromium.org
BUG=358212

Review URL: https://codereview.chromium.org/596663004

git-svn-id: svn://svn.chromium.org/blink/trunk@183192 bbb929c8-8fbe-4397-9dbb-9b2b20218538