ServiceWorker: Implement navigator.serviceWorker.getRegistration [1/3]

ServiceWorker: Implement navigator.serviceWorker.getRegistration [1/3]

This is the first step towards implementing getRegistration method of
ServiceWorkerContainer. This patch adds definition of the method and
its callback type to WebServiceWorkerProvider.

[2/3] https://codereview.chromium.org/535753002/
[3/3] https://codereview.chromium.org/540823003/

BUG=404951
TEST=compile (tests will be added by subsequent patches)

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=181784

[Kunihiko Sakamoto, 2014-09-09 07:26:10]

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

[nhiroki, 2014-09-10 03:08:23]

lgtm

[horo, 2014-09-10 07:34:19]

lgtm

[Kunihiko Sakamoto, 2014-09-10 08:19:33]

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

[Kunihiko Sakamoto, 2014-09-10 08:19:33]

+tkent for OWNERS review

[tkent, 2014-09-10 23:37:42]

The CQ bit was checked by tkent@chromium.org

[tkent, 2014-09-10 23:37:43]

lgtm

[commit-bot: I haz the power, 2014-09-10 23:38:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/553983010/1

[commit-bot: I haz the power, 2014-09-11 01:56:39]

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

[commit-bot: I haz the power, 2014-09-11 01:56:40]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/26524)

[Kunihiko Sakamoto, 2014-09-11 01:59:10]

The CQ bit was checked by ksakamoto@chromium.org

[commit-bot: I haz the power, 2014-09-11 01:59:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/553983010/1

[commit-bot: I haz the power, 2014-09-11 02:41:15]

Committed patchset #1 (id:1) as 181784