Simplify SharedWorkerRepository code

Simplify SharedWorkerRepository code

- Use per-page client model rather than weird static methods
- Stop using custom RuntimeFeature code
- Remove dead/unnecessary code

Deprecating following Blink API (multi-sided):
- WebKit::WebFrameClient::createSharedWorker()
- WebKit::setSharedWorkerRepository()

Instead adding:
- WebKit::WebView::setSharedWorkerRepositoryClient()

Chromium-side patch: https://codereview.chromium.org/40303002/

BUG=none

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=160520

[kinuko, 2013-10-24 14:36:08]

I'd like to cleanup the SharedWorkerRepository code like this way-- can you take
a look?

[abarth-chromium, 2013-10-24 14:45:54]

This looks great.  LGTM.  Thanks!

[commit-bot: I haz the power, 2013-10-24 15:10:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinuko@chromium.org/40143003/90002

[commit-bot: I haz the power, 2013-10-24 15:26:21]

Retried try job too often on blink_presubmit for step(s) presubmit
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=blink_pres...

[commit-bot: I haz the power, 2013-10-25 01:26:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinuko@chromium.org/40143003/90002

[commit-bot: I haz the power, 2013-10-25 02:34:27]

Change committed as 160520