Revert of Delete Rtx-related methods from RTPPayloadRegistry.

Revert of Delete Rtx-related methods from RTPPayloadRegistry. (patchset #3 id:40001 of https://codereview.webrtc.org/3006993002/ )

Reason for revert:
This has to be reverted to enable reverting cl https://codereview.webrtc.org/3006063002/, which seems to have broken ulpfec.

Original issue's description:
> Delete Rtx-related methods from RTPPayloadRegistry.
> 
> Delete methods IsRtx, IsEncapsulated and RestoreOriginalPacket.
> 
> BUG=webrtc:7135
> 
> Review-Url: https://codereview.webrtc.org/3006993002
> Cr-Commit-Position: refs/heads/master@{#19739}
> Committed: https://chromium.googlesource.com/external/webrtc/+/5b4b52264132eefba10bc6880871715f9692da90

TBR=stefan@webrtc.org,danilchap@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7135
Review-Url: https://codereview.webrtc.org/3011093002
Cr-Commit-Position: refs/heads/master@{#19742}
Committed: https://chromium.googlesource.com/external/webrtc/+/a64685325c2f8f51873b67ae8a91f94ffb19d70b

[nisse-webrtc, 2017-09-08 12:00:37]

The CQ bit was checked by nisse@webrtc.org

[nisse-webrtc, 2017-09-08 12:00:37]

Created Revert of Delete Rtx-related methods from RTPPayloadRegistry.

[commit-bot: I haz the power, 2017-09-08 12:00:51]

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, 2017-09-08 12:00:55]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1504872037208090, "parent_rev":
"9bc599f6da435acba6fbb2e5e8b43863dcc45c2b", "commit_rev":
"a64685325c2f8f51873b67ae8a91f94ffb19d70b"}

[commit-bot: I haz the power, 2017-09-08 12:01:00]

Description was changed from

==========
Revert of Delete Rtx-related methods from RTPPayloadRegistry. (patchset #3
id:40001 of https://codereview.webrtc.org/3006993002/ )

Reason for revert:
This has to be reverted to enable reverting cl
https://codereview.webrtc.org/3006063002/, which seems to have broken ulpfec.

Original issue's description:
> Delete Rtx-related methods from RTPPayloadRegistry.
> 
> Delete methods IsRtx, IsEncapsulated and RestoreOriginalPacket.
> 
> BUG=webrtc:7135
> 
> Review-Url: https://codereview.webrtc.org/3006993002
> Cr-Commit-Position: refs/heads/master@{#19739}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/5b4b52264132eefba10bc6880...

TBR=stefan@webrtc.org,danilchap@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7135
==========

to

==========
Revert of Delete Rtx-related methods from RTPPayloadRegistry. (patchset #3
id:40001 of https://codereview.webrtc.org/3006993002/ )

Reason for revert:
This has to be reverted to enable reverting cl
https://codereview.webrtc.org/3006063002/, which seems to have broken ulpfec.

Original issue's description:
> Delete Rtx-related methods from RTPPayloadRegistry.
> 
> Delete methods IsRtx, IsEncapsulated and RestoreOriginalPacket.
> 
> BUG=webrtc:7135
> 
> Review-Url: https://codereview.webrtc.org/3006993002
> Cr-Commit-Position: refs/heads/master@{#19739}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/5b4b52264132eefba10bc6880...

TBR=stefan@webrtc.org,danilchap@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7135

Review-Url: https://codereview.webrtc.org/3011093002
Cr-Commit-Position: refs/heads/master@{#19742}
Committed:
https://chromium.googlesource.com/external/webrtc/+/a64685325c2f8f51873b67ae8...
==========

[commit-bot: I haz the power, 2017-09-08 12:01:01]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/a64685325c2f8f51873b67ae8...

[nisse-webrtc, 2017-09-13 13:15:22]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.webrtc.org/3012253002/ by nisse@webrtc.org.

The reason for reverting is: The cl this change depended on has now been
successfully relanded..