CPUProfiler: linkify scripts even if they have no url

Evals have script body but usually have no url.
We can jump to the source with help of scriptId.

BUG=none
R=vsevik@chromium.org

Review URL: https://codereview.chromium.org/27007002

git-svn-id: svn://svn.chromium.org/blink/trunk@159444 bbb929c8-8fbe-4397-9dbb-9b2b20218538