ServiceWorker: Remove redundant state declarations.

Remove these states as Chromium doesn't need it anymore.

BUG=375132
TBR=abarth@chromium.org

Review URL: https://codereview.chromium.org/383583005

git-svn-id: svn://svn.chromium.org/blink/trunk@178050 bbb929c8-8fbe-4397-9dbb-9b2b20218538