Revert of Remove raw handles from base::win::RegKey

Revert of Remove raw handles from base::win::RegKey (patchset #6 id:330001 of https://codereview.chromium.org/632833002/)

Reason for revert:
Causing base_unittests failures on XP Tests (1)

Original issue's description:
> Remove raw handles from base::win::RegKey
>
> BUG=419210, 423634
> R=cpu@chromium.org, eroman@chromium.org, sky@chromium.org
>
> Committed: https://crrev.com/1aa0fa75b65f403e08ae0f3f2fcb053c02cd9ef2
> Cr-Commit-Position: refs/heads/master@{#299737}

TBR=cpu@chromium.org,eroman@chromium.org,jam@chromium.org,rvargas@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=419210, 423634
Committed: https://crrev.com/4fe6ccadfda8e661ef22a5ab1ce4702f4d363d36
Cr-Commit-Position: refs/heads/master@{#299828}

[dcheng, 2014-10-16 03:05:10]

Created Revert of Remove raw handles from base::win::RegKey

[commit-bot: I haz the power, 2014-10-16 03:07:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/652903005/1

[commit-bot: I haz the power, 2014-10-16 03:09:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-16 03:10:19]

Patchset 1 (id:??) landed as
https://crrev.com/4fe6ccadfda8e661ef22a5ab1ce4702f4d363d36
Cr-Commit-Position: refs/heads/master@{#299828}