ServiceWorker: Remove the obsolete "parsed" state [3/3]

Spec: https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#service-worker-state

[1] Blink: https://codereview.chromium.org/678253002/
[2] Chromium: https://codereview.chromium.org/685503004/
[3] Blink: THIS PATCH

BUG=424081
TEST=run-webkit-tests --debug http/tests/serviceworker/

Review URL: https://codereview.chromium.org/683733002

git-svn-id: svn://svn.chromium.org/blink/trunk@184520 bbb929c8-8fbe-4397-9dbb-9b2b20218538