Reland of Unify rtcp packet setters

Reland of Unify rtcp packet setters (patchset #1 id:1 of https://codereview.webrtc.org/2372713005/ )

Reason for revert:
Fix backward compatibility support

Original issue's description:
> 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}

TBR=sprang@webrtc.org,stefan@webrtc.org,kjellander@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/822a16f64c1fd9b5219e5fea6e5f731ffcd2a2e1
Cr-Commit-Position: refs/heads/master@{#14402}

[danilchap, 2016-09-27 15:51:11]

Created Reland of Unify rtcp packet setters

[danilchap, 2016-09-27 16:27:17]

The CQ bit was checked by danilchap@webrtc.org

[commit-bot: I haz the power, 2016-09-27 16:27:28]

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 16:27:50]

Committed patchset #2 (id:300001)

[commit-bot: I haz the power, 2016-09-27 16:27:55]

Description was changed from

==========
Reland of Unify rtcp packet setters (patchset #1 id:1 of
https://codereview.webrtc.org/2372713005/ )

Reason for revert:
Fix backward compatibility support

Original issue's description:
> 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}

TBR=sprang@webrtc.org,stefan@webrtc.org,kjellander@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5260
==========

to

==========
Reland of Unify rtcp packet setters (patchset #1 id:1 of
https://codereview.webrtc.org/2372713005/ )

Reason for revert:
Fix backward compatibility support

Original issue's description:
> 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}

TBR=sprang@webrtc.org,stefan@webrtc.org,kjellander@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/822a16f64c1fd9b5219e5fea6e5f731ffcd2a2e1
Cr-Commit-Position: refs/heads/master@{#14402}
==========

[commit-bot: I haz the power, 2016-09-27 16:27:56]

Patchset 2 (id:??) landed as
https://crrev.com/822a16f64c1fd9b5219e5fea6e5f731ffcd2a2e1
Cr-Commit-Position: refs/heads/master@{#14402}