Add WebLocalFrame::effectiveSandboxFlags()

Add WebLocalFrame::effectiveSandboxFlags()

We will use it while creating ServiceWorkerNetworkProvider in RenderFrameImpl::didCreateDataSource().
See https://codereview.chromium.org/1191293002/.

BUG=486308
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197698

[horo, 2015-06-23 10:32:51]

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

[horo, 2015-06-23 10:32:51]

kinuko@
Could you please review this?

[kinuko, 2015-06-23 10:45:51]

lgtm

[horo, 2015-06-23 23:21:33]

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

[horo, 2015-06-23 23:21:34]

tkent@
Could you please review this?

Thank you.

[tkent, 2015-06-23 23:37:25]

The CQ bit was checked by tkent@chromium.org

[tkent, 2015-06-23 23:37:25]

lgtm

[commit-bot: I haz the power, 2015-06-23 23:37:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1197383002/1

[commit-bot: I haz the power, 2015-06-24 00:59:01]

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

[commit-bot: I haz the power, 2015-06-24 00:59:02]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/60455)

[horo, 2015-06-24 01:13:46]

The CQ bit was checked by horo@chromium.org

[commit-bot: I haz the power, 2015-06-24 01:14:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1197383002/1

[commit-bot: I haz the power, 2015-06-24 02:33:07]

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

[commit-bot: I haz the power, 2015-06-24 02:33:08]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/60479)

[horo, 2015-06-24 03:40:30]

The CQ bit was checked by horo@chromium.org

[commit-bot: I haz the power, 2015-06-24 03:40:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1197383002/1

[commit-bot: I haz the power, 2015-06-24 04:18:40]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197698