Implement don't step through listed scripts

A derivative work, based on https://chromiumcodereview.appspot.com/17574006/

Review URL: https://chromiumcodereview.appspot.com/19922002

git-svn-id: svn://svn.chromium.org/blink/trunk@155244 bbb929c8-8fbe-4397-9dbb-9b2b20218538