ServiceWorker: Route unregister() through WebServiceWorkerRegistration for refactoring (4)

ServiceWorker: Route unregister() through WebServiceWorkerRegistration for refactoring (4)

This is a part of refactoring CLs for unregister(). See the CL[1] for details.
This CL cleans up transition codes in Chromium.

[1] Blink: https://codereview.chromium.org/1185483003
[2] Chromium: https://codereview.chromium.org/1181973004
[3] Blink: https://codereview.chromium.org/1190503002
[4] Chromium: THIS PATCH

BUG=500404
TEST=content_unittests --gtest_filter=ServiceWorker*

Committed: https://crrev.com/ecf8fa2421b29a84eff93320280afdc70c5a1aaf
Cr-Commit-Position: refs/heads/master@{#335225}

[nhiroki, 2015-06-19 01:34:13]

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

[nhiroki, 2015-06-19 01:34:14]

Ptal, thanks!

[Kunihiko Sakamoto, 2015-06-19 02:04:17]

lgtm

[nhiroki, 2015-06-19 05:25:06]

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

[nhiroki, 2015-06-19 05:25:07]

+mkwst@ for service_worker_messages.h, PTAL

[Mike West, 2015-06-19 05:34:55]

On 2015/06/19 at 05:25:07, nhiroki wrote:
> +mkwst@ for service_worker_messages.h, PTAL

Removing deprecated IPC message LGTM.

[nhiroki, 2015-06-19 06:26:10]

The CQ bit was checked by nhiroki@chromium.org

[commit-bot: I haz the power, 2015-06-19 06:27:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1186803002/40001

[commit-bot: I haz the power, 2015-06-19 08:31:51]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-06-19 08:33:09]

Patchset 3 (id:??) landed as
https://crrev.com/ecf8fa2421b29a84eff93320280afdc70c5a1aaf
Cr-Commit-Position: refs/heads/master@{#335225}