Revert of Prerender: Hardcode the Silence experiment date

Revert of Prerender: Hardcode the Silence experiment date (patchset #3 id:40001 of https://codereview.chromium.org/2538723003/ )

Reason for revert:
too late to get it into M55

Original issue's description:
> Prerender: Hardcode the Silence experiment date
>
> As confirmed with the UMA team, the field trial allows only 60-70% coverage of
> users for one day (particularly, on Windows).
>
> To address this shortcoming, this change hardcodes the explicit date of the
> experiment (for December 14th as seen in PST, to be synchronized with field
> trial server-seeding better). To be effective this must be cherry-picked to M55.
>
> The experiment still has the ability to serve as a "kill switch" by setting the
> group "ExperimentYes_expires_2016-12-14T07:00:00Z" (or any earlier date in the
> string). As discussed above, this has limited effect in the day range.
>
> Also this changes AGSA to opt out of the experiment. Currently AGSA only uses
> ORIGIN_EXTERNAL_REQUEST_FORCED_CELLULAR. The experiment will not take effect
> on these origins. Other 1st party apps are not using this prerender::Origin, as
> far as we know, and the use of it is restricted to 1st party, hence this change
> should not affect the experiment for other Android apps.
>
> BUG=640592
>
> Committed: https://crrev.com/40296583e81a52db397a24b2745f43a35ab6870e
> Cr-Commit-Position: refs/heads/master@{#435610}

TBR=droger@chromium.org,mattcary@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=640592
Committed: https://crrev.com/ce619a3e844f0170c128162ba0f27d0a2bb685e2
Cr-Commit-Position: refs/heads/master@{#436002}

[pasko, 2016-12-02 19:10:00]

The CQ bit was checked by pasko@chromium.org

[pasko, 2016-12-02 19:10:00]

Created Revert of Prerender: Hardcode the Silence experiment date

[commit-bot: I haz the power, 2016-12-02 19:10:49]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-02 19:59:34]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480705800495270, "parent_rev":
"b2ec0a8c1c3b2199314e13d393081e5ab4503beb", "commit_rev":
"79b513cf89afb8bd51b0c2e5dd9e78ef13f7d445"}

[commit-bot: I haz the power, 2016-12-02 19:59:59]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-02 20:01:55]

Description was changed from

==========
Revert of Prerender: Hardcode the Silence experiment date (patchset #3 id:40001
of https://codereview.chromium.org/2538723003/ )

Reason for revert:
too late to get it into M55

Original issue's description:
> Prerender: Hardcode the Silence experiment date
> 
> As confirmed with the UMA team, the field trial allows only 60-70% coverage of
> users for one day (particularly, on Windows).
> 
> To address this shortcoming, this change hardcodes the explicit date of the
> experiment (for December 14th as seen in PST, to be synchronized with field
> trial server-seeding better). To be effective this must be cherry-picked to
M55.
> 
> The experiment still has the ability to serve as a "kill switch" by setting
the
> group "ExperimentYes_expires_2016-12-14T07:00:00Z" (or any earlier date in the
> string). As discussed above, this has limited effect in the day range.
> 
> Also this changes AGSA to opt out of the experiment. Currently AGSA only uses
> ORIGIN_EXTERNAL_REQUEST_FORCED_CELLULAR. The experiment will not take effect
> on these origins. Other 1st party apps are not using this prerender::Origin,
as
> far as we know, and the use of it is restricted to 1st party, hence this
change
> should not affect the experiment for other Android apps.
> 
> BUG=640592
> 
> Committed: https://crrev.com/40296583e81a52db397a24b2745f43a35ab6870e
> Cr-Commit-Position: refs/heads/master@{#435610}

TBR=droger@chromium.org,mattcary@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=640592
==========

to

==========
Revert of Prerender: Hardcode the Silence experiment date (patchset #3 id:40001
of https://codereview.chromium.org/2538723003/ )

Reason for revert:
too late to get it into M55

Original issue's description:
> Prerender: Hardcode the Silence experiment date
>
> As confirmed with the UMA team, the field trial allows only 60-70% coverage of
> users for one day (particularly, on Windows).
>
> To address this shortcoming, this change hardcodes the explicit date of the
> experiment (for December 14th as seen in PST, to be synchronized with field
> trial server-seeding better). To be effective this must be cherry-picked to
M55.
>
> The experiment still has the ability to serve as a "kill switch" by setting
the
> group "ExperimentYes_expires_2016-12-14T07:00:00Z" (or any earlier date in the
> string). As discussed above, this has limited effect in the day range.
>
> Also this changes AGSA to opt out of the experiment. Currently AGSA only uses
> ORIGIN_EXTERNAL_REQUEST_FORCED_CELLULAR. The experiment will not take effect
> on these origins. Other 1st party apps are not using this prerender::Origin,
as
> far as we know, and the use of it is restricted to 1st party, hence this
change
> should not affect the experiment for other Android apps.
>
> BUG=640592
>
> Committed: https://crrev.com/40296583e81a52db397a24b2745f43a35ab6870e
> Cr-Commit-Position: refs/heads/master@{#435610}

TBR=droger@chromium.org,mattcary@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=640592

Committed: https://crrev.com/ce619a3e844f0170c128162ba0f27d0a2bb685e2
Cr-Commit-Position: refs/heads/master@{#436002}
==========

[commit-bot: I haz the power, 2016-12-02 20:01:56]

Patchset 1 (id:??) landed as
https://crrev.com/ce619a3e844f0170c128162ba0f27d0a2bb685e2
Cr-Commit-Position: refs/heads/master@{#436002}