Revert of Re-enable the new SQLitePersistentCookieStore load strategy.

Revert of Re-enable the new SQLitePersistentCookieStore load strategy. (patchset #1 id:1 of https://codereview.chromium.org/953993002/)

Reason for revert:
This CL causes hangs during shutdown.

https://code.google.com/p/chromium/issues/detail?id=465271

Original issue's description:
> Re-enable the new SQLitePersistentCookieStore load strategy.
>
> When I first turned on the new load strategy, it caused deadlocks during
> shutdown. I found and fixed the bug in SequencedWorkerPool.
>
> BUG=448910
>
> Committed: https://crrev.com/043d6b497dda7a39138eca1fb9df89ee340e543b
> Cr-Commit-Position: refs/heads/master@{#318305}

TBR=erikwright@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=448910
Committed: https://crrev.com/24ab88b28d3fcdb67a919527e67c49ba5d55ed93
Cr-Commit-Position: refs/heads/master@{#319696}

[erikchen, 2015-03-09 18:35:43]

Created Revert of Re-enable the new SQLitePersistentCookieStore load strategy.

[commit-bot: I haz the power, 2015-03-09 18:36:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/992723002/1

[commit-bot: I haz the power, 2015-03-09 18:37:52]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-09 18:38:28]

Patchset 1 (id:??) landed as
https://crrev.com/24ab88b28d3fcdb67a919527e67c49ba5d55ed93
Cr-Commit-Position: refs/heads/master@{#319696}

[erikchen, 2015-03-13 23:47:26]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1005953003/ by erikchen@chromium.org.

The reason for reverting is: The source of the crash was another bug in
SequencedWorkerPool. I just landed a fix for that:
https://codereview.chromium.org/994483005/

So I'm going to reland this CL..