Revert of Suppress Uninitialized access in ExtensionManagement::Refresh

Revert of Suppress Uninitialized access in ExtensionManagement::Refresh (patchset #2 id:20001 of https://codereview.chromium.org/608063002/)

Reason for revert:
The Clang roll that caused the Valgrind error was reverted in https://chromium.googlesource.com/chromium/src/+/3c80ac9fd48da3d11852eecd6999053d6d84c56c

Original issue's description:
> Suppress Uninitialized access in ExtensionManagement::Refresh
>
> BUG=418234
> TBR=miu@chromium.org
>
> Committed: https://crrev.com/459b9796ff2ba105e8a6bae4c7e63508ea83bb67
> Cr-Commit-Position: refs/heads/master@{#297028}

TBR=miu@chromium.org,oshima@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=418234
Committed: https://crrev.com/830628b83527701019e94e2d5f75d4dc4c3cb5b0
Cr-Commit-Position: refs/heads/master@{#297074}

[hans, 2014-09-26 23:48:26]

Created Revert of Suppress Uninitialized access in ExtensionManagement::Refresh

[commit-bot: I haz the power, 2014-09-26 23:48:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/610753002/1

[commit-bot: I haz the power, 2014-09-26 23:49:51]

Committed patchset #1 (id:1) as 8d252a61fc8c034b34d426a3acf8b223fb92c8c0

[commit-bot: I haz the power, 2014-09-26 23:50:30]

Patchset 1 (id:??) landed as
https://crrev.com/830628b83527701019e94e2d5f75d4dc4c3cb5b0
Cr-Commit-Position: refs/heads/master@{#297074}

[miu, 2014-09-26 23:55:19]

lgtm