ServiceWorker: Route unregister() through WebServiceWorkerRegistration for refactoring (2)
This is a part of refactoring CLs for unregister(). See the CL[1] for details.
This CL renames existing Unregister* for "pattern" to DeprecatedUnregister*,
and adds new Unregister* for "registration_id".
Blink: https://codereview.chromium.org/1185483003
[2] Chromium: THIS PATCH
Blink: https://codereview.chromium.org/1190503002
[4] Chromium: https://codereview.chromium.org/
1186803002
BUG=500404
TEST=compile
Review URL: https://codereview.chromium.org/
1181973004
Cr-Commit-Position: refs/heads/master@{#335009}