ServiceWorker: "minimal" end-to-end sample as a W3C test

A few NYI things are commented out.

Also removes [NoInterfaceObject] from ServiceWorkerContainer since
script should be able to see the type.

Review URL: https://codereview.chromium.org/238993003

git-svn-id: svn://svn.chromium.org/blink/trunk@173022 bbb929c8-8fbe-4397-9dbb-9b2b20218538