Revert of Unify rtcp packet setters

Revert of Unify rtcp packet setters (patchset #8 id:130001 of https://codereview.webrtc.org/2348623003/ )

Reason for revert:
Breaks compilation of internal downstream project.

Original issue's description:
> Unify rtcp packet setters
> Renamed setters in rtcp classes
> from WithField to SetField
> from WithItem to AddItem or SetItems
> from From to SetSenderSsrc
> from To to SetMediaSsrc
> Some redundant or unsued setters removed.
> Pass-by-const& replaced with pass-by-value when appropriate.
>
> BUG=webrtc:5260
>
> Committed: https://crrev.com/20e77c7b8a9f19942ef3c3c4f1fa3888b2cd54ea
> Cr-Commit-Position: refs/heads/master@{#14393}

TBR=sprang@webrtc.org,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:5260
Committed: https://crrev.com/efc6e41866662e0922858fbce1d9ee3bdd0637ed
Cr-Commit-Position: refs/heads/master@{#14400}

[kjellander_webrtc, 2016-09-27 15:39:09]

The CQ bit was checked by kjellander@webrtc.org

[kjellander_webrtc, 2016-09-27 15:39:10]

Created Revert of Unify rtcp packet setters

[commit-bot: I haz the power, 2016-09-27 15:39:22]

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, 2016-09-27 15:39:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-27 15:39:47]

Description was changed from

==========
Revert of Unify rtcp packet setters (patchset #8 id:130001 of
https://codereview.webrtc.org/2348623003/ )

Reason for revert:
Breaks compilation of internal downstream project.

Original issue's description:
> Unify rtcp packet setters
> Renamed setters in rtcp classes
> from WithField to SetField
> from WithItem to AddItem or SetItems
> from From to SetSenderSsrc
> from To to SetMediaSsrc
> Some redundant or unsued setters removed.
> Pass-by-const& replaced with pass-by-value when appropriate.
> 
> BUG=webrtc:5260
> 
> Committed: https://crrev.com/20e77c7b8a9f19942ef3c3c4f1fa3888b2cd54ea
> Cr-Commit-Position: refs/heads/master@{#14393}

TBR=sprang@webrtc.org,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:5260
==========

to

==========
Revert of Unify rtcp packet setters (patchset #8 id:130001 of
https://codereview.webrtc.org/2348623003/ )

Reason for revert:
Breaks compilation of internal downstream project.

Original issue's description:
> Unify rtcp packet setters
> Renamed setters in rtcp classes
> from WithField to SetField
> from WithItem to AddItem or SetItems
> from From to SetSenderSsrc
> from To to SetMediaSsrc
> Some redundant or unsued setters removed.
> Pass-by-const& replaced with pass-by-value when appropriate.
>
> BUG=webrtc:5260
>
> Committed: https://crrev.com/20e77c7b8a9f19942ef3c3c4f1fa3888b2cd54ea
> Cr-Commit-Position: refs/heads/master@{#14393}

TBR=sprang@webrtc.org,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:5260

Committed: https://crrev.com/efc6e41866662e0922858fbce1d9ee3bdd0637ed
Cr-Commit-Position: refs/heads/master@{#14400}
==========

[commit-bot: I haz the power, 2016-09-27 15:39:48]

Patchset 1 (id:??) landed as
https://crrev.com/efc6e41866662e0922858fbce1d9ee3bdd0637ed
Cr-Commit-Position: refs/heads/master@{#14400}

[danilchap, 2016-09-27 15:51:10]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.webrtc.org/2370313002/ by danilchap@webrtc.org.

The reason for reverting is: Fix backward compatibility support.