Expose WebView::setOpenedByDOM.

Expose WebView::setOpenedByDOM.

Sets the openedByDOM bit on the Page. This is used to determine whether
window.close() may be called. Expose this so the state may be managed by the
WebContents and plumbed down as Pages are created.

A follow-up change will remove the two existing calls to Page::setOpenedByDOM
after the value becomes managed by Chromium.

BUG=357579
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171167

[davidben, 2014-04-09 16:28:37]

abarth: This is to be used with https://codereview.chromium.org/212703005/ to
synchronous the state across process swaps. The Chromium CL will be followed up
with https://codereview.chromium.org/224173007/ since those calls will then be
redundant.

creis: FYI.

[abarth-chromium, 2014-04-09 17:28:05]

lgtm

[davidben, 2014-04-09 18:16:29]

The CQ bit was checked by davidben@chromium.org

[commit-bot: I haz the power, 2014-04-09 18:16:33]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/davidben@chromium.org/223603005/20001

[commit-bot: I haz the power, 2014-04-09 19:08:36]

Change committed as 171167