[ServiceWorker] Use WebPageVisibilityState in ClientInfo.

[ServiceWorker] Use WebPageVisibilityState in ClientInfo.

That means setting pageVisibilityState in WebServiceWorkerClientInfo and
use page_visibility_state instead of visibilyt_state in ServiceWorkerInfo.

In addition, this CL uses WebPageVisibilityState.h from public/platform/
instead of public/web/.

This is part of a three-sided CL:
- https://codereview.chromium.org/844733003/
- <this>
- https://codereview.chromium.org/831483003

BUG=447212
Committed: https://crrev.com/3c578ba82c786e4c76f934ee234fa2576372ee3c
Cr-Commit-Position: refs/heads/master@{#310988}

[mlamouri (slow - plz ping), 2015-01-09 11:15:08]

mlamouri@chromium.org changed reviewers:
+ jochen@chromium.org, mkwst@chromium.org, nasko@chromium.org

[mlamouri (slow - plz ping), 2015-01-09 11:15:08]

mlamouri@chromium.org changed required reviewers:
+ jochen@chromium.org, nasko@chromium.org

[mlamouri (slow - plz ping), 2015-01-09 11:15:09]

jochen@, please review changes in:
- chrome/browser/DEPS

nasko@, please review changes in:
- *

mkwst@, I have added you FYI, given that you should be on the hook for parts 1
and 3 ;)

[jochen (gone - plz use gerrit), 2015-01-09 13:05:44]

jochen@chromium.org changed required reviewers:
- jochen@chromium.org, nasko@chromium.org

[jochen (gone - plz use gerrit), 2015-01-09 13:05:45]

lgtm

[nasko, 2015-01-09 18:27:00]

LGTM

[Mike West, 2015-01-09 22:21:57]

LGTM3.

[mlamouri (slow - plz ping), 2015-01-10 17:21:00]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2015-01-10 17:21:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/806703004/1

[commit-bot: I haz the power, 2015-01-10 19:02:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-10 19:03:31]

Patchset 1 (id:??) landed as
https://crrev.com/3c578ba82c786e4c76f934ee234fa2576372ee3c
Cr-Commit-Position: refs/heads/master@{#310988}