Add field trial for disallowing fetch of doc.written scripts.

Add field trial for disallowing fetch of doc.written scripts.

BUG=594159
Committed: https://crrev.com/4bdb3bffcb7a93451ce52d218b99ecc87c7b7348
Cr-Commit-Position: refs/heads/master@{#384618}

[Bryan McQuade, 2016-04-01 13:22:05]

bmcquade@chromium.org changed reviewers:
+ jkarlin@chromium.org, shivanisha@chromium.org

[Bryan McQuade, 2016-04-01 13:23:46]

PTAL.

I previously added some shared plumbing code in chrome_content_browser_client.cc
for enabling field trials based on blink settings values. This change leverages
that code to add a field trial name for our existing blink setting to disable
load of doc.written scripts in the main frame. We are still lacking support for
varying this behavior based on connection type, but I figure I'd get this landed
now so we have it for 51, while Shivani drives the work to add support for
varying based on connection type.

[jkarlin, 2016-04-01 16:51:31]

lgtm!

[Bryan McQuade, 2016-04-01 16:52:04]

The CQ bit was checked by bmcquade@chromium.org

[commit-bot: I haz the power, 2016-04-01 16:52:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1854703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1854703002/1

[shivanisha, 2016-04-01 16:55:39]

On 2016/04/01 at 16:52:25, commit-bot wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1854703002/1
> View timeline at
>  https://chromium-cq-status.appspot.com/patch-timeline/1854703002/1

lgtm

[commit-bot: I haz the power, 2016-04-01 17:32:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-01 17:34:58]

Description was changed from

==========
Add field trial for disallowing fetch of doc.written scripts.

BUG=594159
==========

to

==========
Add field trial for disallowing fetch of doc.written scripts.

BUG=594159

Committed: https://crrev.com/4bdb3bffcb7a93451ce52d218b99ecc87c7b7348
Cr-Commit-Position: refs/heads/master@{#384618}
==========

[commit-bot: I haz the power, 2016-04-01 17:34:59]

Patchset 1 (id:??) landed as
https://crrev.com/4bdb3bffcb7a93451ce52d218b99ecc87c7b7348
Cr-Commit-Position: refs/heads/master@{#384618}