Delete unused class rtc::RegKey.

Delete unused class rtc::RegKey.

BUG=webrtc:6424
Committed: https://crrev.com/db397429d4d4d0bdf39cfe4da4628309e366dc80
Cr-Commit-Position: refs/heads/master@{#15592}

[nisse-webrtc, 2016-12-13 10:45:11]

nisse@webrtc.org changed reviewers:
+ pthatcher@webrtc.org

[pthatcher1, 2016-12-13 22:58:58]

lgtm

[nisse-webrtc, 2016-12-14 07:35:51]

The CQ bit was checked by nisse@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-14 07:35:53]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2016-12-14 08:25:55]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-14 08:25:56]

Dry run: This issue passed the CQ dry run.

[nisse-webrtc, 2016-12-14 08:28:32]

The CQ bit was checked by nisse@webrtc.org

[commit-bot: I haz the power, 2016-12-14 08:28:40]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2016-12-14 08:30:28]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481704112725140, "parent_rev":
"7c78534c1bc4cd1050d163bac0022abb19b9a4ba", "commit_rev":
"97986506457efd343b6b8894286c2abed95d4bac"}

[commit-bot: I haz the power, 2016-12-14 08:30:30]

Description was changed from

==========
Delete unused class rtc::RegKey.

BUG=webrtc:6424
==========

to

==========
Delete unused class rtc::RegKey.

BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2571763002
==========

[commit-bot: I haz the power, 2016-12-14 08:30:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-14 08:30:39]

Description was changed from

==========
Delete unused class rtc::RegKey.

BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2571763002
==========

to

==========
Delete unused class rtc::RegKey.

BUG=webrtc:6424

Committed: https://crrev.com/db397429d4d4d0bdf39cfe4da4628309e366dc80
Cr-Commit-Position: refs/heads/master@{#15592}
==========

[commit-bot: I haz the power, 2016-12-14 08:30:43]

Patchset 1 (id:??) landed as
https://crrev.com/db397429d4d4d0bdf39cfe4da4628309e366dc80
Cr-Commit-Position: refs/heads/master@{#15592}