ServiceWorker: Route unregister() through WebServiceWorkerRegistration for refactoring (3)

ServiceWorker: Route unregister() through WebServiceWorkerRegistration for refactoring (3)

This is a part of refactoring CLs for unregister(). See the CL[1] for details.
This CL actually switches unregister() callpath.

[1] Blink: https://codereview.chromium.org/1185483003/
[2] Chromium: https://codereview.chromium.org/1181973004
[3] Blink: THIS PATCH
[4] Chromium: https://codereview.chromium.org/1186803002

BUG=500404
TEST=run_layout_tests.sh http/tests/serviceworker/

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197421

[nhiroki, 2015-06-16 02:08:16]

nhiroki@chromium.org changed reviewers:
+ kinuko@chromium.org

[nhiroki, 2015-06-16 02:08:16]

ptal

[nhiroki, 2015-06-19 00:39:46]

The CQ bit was checked by nhiroki@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-06-19 00:39:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1190503002/20001

[commit-bot: I haz the power, 2015-06-19 00:49:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-19 00:49:00]

Dry run: Try jobs failed on following builders:
  linux_chromium_gn_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/linux_chromium_gn_rel/bu...)

[nhiroki, 2015-06-19 01:33:17]

nhiroki@chromium.org changed reviewers:
+ ksakamoto@chromium.org

[nhiroki, 2015-06-19 01:33:17]

ksakamoto@, can you take a look at this?

[Kunihiko Sakamoto, 2015-06-19 01:57:10]

lgtm

[nhiroki, 2015-06-19 02:00:21]

nhiroki@chromium.org changed reviewers:
+ tkent@chromium.org

[nhiroki, 2015-06-19 02:00:22]

+tkent@ for WebServiceWorkerProvider.h, PTAL

[tkent, 2015-06-19 02:13:21]

lgtm

[nhiroki, 2015-06-19 02:13:56]

The CQ bit was checked by nhiroki@chromium.org

[commit-bot: I haz the power, 2015-06-19 02:14:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1190503002/20001

[commit-bot: I haz the power, 2015-06-19 02:30:57]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197421