[DevTools] Add "Show all" check box in Service Worker view.

There are some requests from web developers to provide a way to debug SWs before opening the page.
This cl adds "Show all" check box which shows all SWs in DevTools.

BUG=597538

Review URL: https://codereview.chromium.org/1853073003

Cr-Commit-Position: refs/heads/master@{#385372}
2 files changed