Revert of Revert of [MemSherrif] Uninitialized Read

Revert of Revert of [MemSherrif] Uninitialized Read (patchset #2 id:40001 of https://codereview.chromium.org/986763002/)

Reason for revert:
DrMemory bots still hit the bug: http://build.chromium.org/p/chromium.memory.fyi/builders/Windows%20Content%20Browser%20%28DrMemory%20full%29%20%286%29/builds/3752

Original issue's description:
> Revert of [MemSherrif] Uninitialized Read (patchset #1 id:1 of https://codereview.chromium.org/969073002/)
>
> Reason for revert:
> Uninitialized read should now be fixed (and there is a test). Should this revert break the DrMemory bots, this revert should be reverted.
>
> Original issue's description:
> > [MemSherrif] Uninitialized Read
> >
> > BUG=463204
> > TBR=reed@chromium.org, thestig@chromium.org
> >
> > Committed: https://crrev.com/94d1b7498d7b5c4fc25e3337be117f8c9ef1dbf2
> > Cr-Commit-Position: refs/heads/master@{#318760}
>
> TBR=thestig@chromium.org,groby@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=463204
>
> Committed: https://crrev.com/82417f64ce69c98a93f82f59e6adda1c9c2e510c
> Cr-Commit-Position: refs/heads/master@{#319503}

TBR=groby@chromium.org,bungeman@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=463204
Committed: https://crrev.com/5b0767c2297b1b83f6ecfd924bd0c221a942ebe0
Cr-Commit-Position: refs/heads/master@{#319553}

[Lei Zhang, 2015-03-07 03:59:48]

Created Revert of Revert of [MemSherrif] Uninitialized Read

[commit-bot: I haz the power, 2015-03-07 04:00:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/984073007/1

[Lei Zhang, 2015-03-07 04:00:21]

If you look at the previous run:
http://build.chromium.org/p/chromium.memory.fyi/builders/Windows%20Content%20...
and search for "463204", you would have seen the suppression was still in use.

[commit-bot: I haz the power, 2015-03-07 04:01:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-07 04:01:56]

Patchset 1 (id:??) landed as
https://crrev.com/5b0767c2297b1b83f6ecfd924bd0c221a942ebe0
Cr-Commit-Position: refs/heads/master@{#319553}

[groby-ooo-7-16, 2015-03-09 21:09:24]

On 2015/03/07 04:01:56, I haz the power (commit-bot) wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/5b0767c2297b1b83f6ecfd924bd0c221a942ebe0
> Cr-Commit-Position: refs/heads/master@{#319553}

LGTM