Revert of Protect new header extension by field trial experiment to allow hardcoding it in SDP

Revert of Protect new header extension by field trial experiment to allow hardcoding it in SDP (patchset #3 id:40001 of https://codereview.webrtc.org/2922683002/ )

Reason for revert:
Breaks tests in downstream projects.

Original issue's description:
> Protect new header extension by field trial experiment to allow hardcoding it in SDP
> 
> BUG=chrome:718738
> 
> Review-Url: https://codereview.webrtc.org/2922683002
> Cr-Commit-Position: refs/heads/master@{#18409}
> Committed: https://chromium.googlesource.com/external/webrtc/+/cafa1d6bbef79d9a8507c6e782f3c7824ef1070b

TBR=sprang@webrtc.org,asapersson@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chrome:718738
Review-Url: https://codereview.webrtc.org/2922723002
Cr-Commit-Position: refs/heads/master@{#18414}
Committed: https://chromium.googlesource.com/external/webrtc/+/ed9b9ff5973579cb8cb25aa4cc299b810e151ac0

[ilnik, 2017-06-02 14:29:52]

The CQ bit was checked by ilnik@webrtc.org

[ilnik, 2017-06-02 14:29:52]

Created Revert of Protect new header extension by field trial experiment to
allow hardcoding it in SDP

[commit-bot: I haz the power, 2017-06-02 14:29:59]

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, 2017-06-02 14:30:20]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496413792125150, "parent_rev":
"dc2018b87ffc56fc668da684787c9f6cdc210034", "commit_rev":
"ed9b9ff5973579cb8cb25aa4cc299b810e151ac0"}

[commit-bot: I haz the power, 2017-06-02 14:30:23]

Description was changed from

==========
Revert of Protect new header extension by field trial experiment to allow
hardcoding it in SDP (patchset #3 id:40001 of
https://codereview.webrtc.org/2922683002/ )

Reason for revert:
Breaks tests in downstream projects.

Original issue's description:
> Protect new header extension by field trial experiment to allow hardcoding it
in SDP
> 
> BUG=chrome:718738
> 
> Review-Url: https://codereview.webrtc.org/2922683002
> Cr-Commit-Position: refs/heads/master@{#18409}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/cafa1d6bbef79d9a8507c6e78...

TBR=sprang@webrtc.org,asapersson@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chrome:718738
==========

to

==========
Revert of Protect new header extension by field trial experiment to allow
hardcoding it in SDP (patchset #3 id:40001 of
https://codereview.webrtc.org/2922683002/ )

Reason for revert:
Breaks tests in downstream projects.

Original issue's description:
> Protect new header extension by field trial experiment to allow hardcoding it
in SDP
> 
> BUG=chrome:718738
> 
> Review-Url: https://codereview.webrtc.org/2922683002
> Cr-Commit-Position: refs/heads/master@{#18409}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/cafa1d6bbef79d9a8507c6e78...

TBR=sprang@webrtc.org,asapersson@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chrome:718738

Review-Url: https://codereview.webrtc.org/2922723002
Cr-Commit-Position: refs/heads/master@{#18414}
Committed:
https://chromium.googlesource.com/external/webrtc/+/ed9b9ff5973579cb8cb25aa4c...
==========

[commit-bot: I haz the power, 2017-06-02 14:30:24]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/ed9b9ff5973579cb8cb25aa4c...

[ilnik, 2017-06-05 08:25:37]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.webrtc.org/2922953002/ by ilnik@webrtc.org.

The reason for reverting is: Fixes in downstream projects are done..