Revert of Delete unused class/template ScopedMessageData.

Revert of Delete unused class/template ScopedMessageData. (patchset #1 id:1 of https://codereview.webrtc.org/2652663002/ )

Reason for revert:
ScopedMessageData can't be removed just yet. It broke an internal project.

Original issue's description:
> Delete unused class/template ScopedMessageData.
> 
> This appears unused since cl https://codereview.webrtc.org/2564333002
> 
> BUG=webrtc:6424
> 
> Review-Url: https://codereview.webrtc.org/2652663002
> Cr-Commit-Position: refs/heads/master@{#16229}
> Committed: https://chromium.googlesource.com/external/webrtc/+/d83fb921a855531bfa58f873e2c668bfa735ad09

TBR=pthatcher@webrtc.org,deadbeef@webrtc.org,nisse@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6424
Review-Url: https://codereview.webrtc.org/2654753003
Cr-Commit-Position: refs/heads/master@{#16231}
Committed: https://chromium.googlesource.com/external/webrtc/+/e04064deb2d7a49493bdeac0c87f7e0aa0fa141c

[aleloi, 2017-01-24 09:20:25]

The CQ bit was checked by aleloi@webrtc.org

[aleloi, 2017-01-24 09:20:25]

Created Revert of Delete unused class/template ScopedMessageData.

[commit-bot: I haz the power, 2017-01-24 09:20:35]

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, 2017-01-24 09:20:40]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1485249625160930, "parent_rev":
"dc2b3f3b9f694bfc738c491abb76ca1382c1c0e1", "commit_rev":
"e04064deb2d7a49493bdeac0c87f7e0aa0fa141c"}

[commit-bot: I haz the power, 2017-01-24 09:20:42]

Description was changed from

==========
Revert of Delete unused class/template ScopedMessageData. (patchset #1 id:1 of
https://codereview.webrtc.org/2652663002/ )

Reason for revert:
ScopedMessageData can't be removed just yet. It broke an internal project.

Original issue's description:
> Delete unused class/template ScopedMessageData.
> 
> This appears unused since cl https://codereview.webrtc.org/2564333002
> 
> BUG=webrtc:6424
> 
> Review-Url: https://codereview.webrtc.org/2652663002
> Cr-Commit-Position: refs/heads/master@{#16229}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/d83fb921a855531bfa58f873e...

TBR=pthatcher@webrtc.org,deadbeef@webrtc.org,nisse@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6424
==========

to

==========
Revert of Delete unused class/template ScopedMessageData. (patchset #1 id:1 of
https://codereview.webrtc.org/2652663002/ )

Reason for revert:
ScopedMessageData can't be removed just yet. It broke an internal project.

Original issue's description:
> Delete unused class/template ScopedMessageData.
> 
> This appears unused since cl https://codereview.webrtc.org/2564333002
> 
> BUG=webrtc:6424
> 
> Review-Url: https://codereview.webrtc.org/2652663002
> Cr-Commit-Position: refs/heads/master@{#16229}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/d83fb921a855531bfa58f873e...

TBR=pthatcher@webrtc.org,deadbeef@webrtc.org,nisse@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2654753003
Cr-Commit-Position: refs/heads/master@{#16231}
Committed:
https://chromium.googlesource.com/external/webrtc/+/e04064deb2d7a49493bdeac0c...
==========

[commit-bot: I haz the power, 2017-01-24 09:20:43]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/e04064deb2d7a49493bdeac0c...