Runtime.CallFrame has url already. It allows to show stack traces on pause
without tacking all parsed scripts.

R=alph@chromium.org,pfeldman@chromium.org

Bug: chromium:762982
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ic4f096ade1cb6c9de42fec77280dcc3007c6a5cf
Reviewed-on: https://chromium-review.googlesource.com/648068
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47895}