Revert of [Extensions] Migrate ServiceWorker off behavior feature system

Revert of [Extensions] Migrate ServiceWorker off behavior feature system (patchset #1 id:1 of https://codereview.chromium.org/1417563005/ )

Reason for revert:
Reverting because this CL appears to be causing failures on this bot: https://build.chromium.org/p/chromium.win/builders/Win%20x64%20Builder%20%28dbg%29/builds/14499 .

Original issue's description:
> [Extensions] Migrate ServiceWorker off behavior feature system
>
> The FeatureSystem is failing to retrieve the behavior feature for service
> workers, but the only reason this seems to be the case is because of
> potential corruption in the JSON files (or the JSON parser otherwise choking).
> For now, to reduce the crash rates, just migrate the service worker restriction
> off the behavior feature system.
>
> BUG=461915
>
> Committed: https://crrev.com/2507a2fcd25244dadb7dfcc316426bee7b1df275
> Cr-Commit-Position: refs/heads/master@{#356123}

TBR=rockot@chromium.org,rdevlin.cronin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=461915
Committed: https://crrev.com/5708524cd0517ad825093d8cb4e9171ca99b3f42
Cr-Commit-Position: refs/heads/master@{#356137}

[anthonyvd, 2015-10-26 21:50:39]

Created Revert of [Extensions] Migrate ServiceWorker off behavior feature system

[commit-bot: I haz the power, 2015-10-26 21:52:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1412683007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1412683007/1

[commit-bot: I haz the power, 2015-10-26 21:55:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-26 21:57:28]

Patchset 1 (id:??) landed as
https://crrev.com/5708524cd0517ad825093d8cb4e9171ca99b3f42
Cr-Commit-Position: refs/heads/master@{#356137}

[Devlin, 2015-10-26 22:11:42]

On 2015/10/26 21:57:28, commit-bot: I haz the power wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/5708524cd0517ad825093d8cb4e9171ca99b3f42
> Cr-Commit-Position: refs/heads/master@{#356137}

(Re-posting on this CL)
> To me, that failure looks like a flake, and it seems like the subsequent build
> succeeded compilation?
> 
>
https://build.chromium.org/p/chromium.win/builders/Win%20x64%20Builder%20%28d...

[Devlin, 2015-10-26 22:24:38]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1406083004/ by rdevlin.cronin@chromium.org.

The reason for reverting is: Talked to Anthony offline and we agreed the error
was probably not my CL..