Revert of Move MutableDataY{,U,V} methods to I420Buffer only.

Revert of Move MutableDataY{,U,V} methods to I420Buffer only. (patchset #14 id:260001 of https://codereview.webrtc.org/2278883002/ )

Reason for revert:
Broke downstream application.

Original issue's description:
> Move MutableDataY{,U,V} methods to I420Buffer only.
>
> Deleted from the VideoFrameBuffer base class.
>
> BUG=webrtc:5921
>
> Committed: https://crrev.com/5539ef6c03c273f39fadae41ace47fdc11ac6d60
> Cr-Commit-Position: refs/heads/master@{#14317}

TBR=perkj@webrtc.org,magjed@webrtc.org,pthatcher@webrtc.org,honghaiz@webrtc.org,stefan@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5921
Committed: https://crrev.com/776870a2599b8f43ad56987f9031690e3ccecde8
Cr-Commit-Position: refs/heads/master@{#14325}

[nisse-webrtc, 2016-09-21 10:51:37]

The CQ bit was checked by nisse@webrtc.org

[nisse-webrtc, 2016-09-21 10:51:37]

Created Revert of Move MutableDataY{,U,V} methods to I420Buffer only.

[commit-bot: I haz the power, 2016-09-21 10:51:46]

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, 2016-09-21 10:52:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-21 10:52:24]

Description was changed from

==========
Revert of Move MutableDataY{,U,V} methods to I420Buffer only. (patchset #14
id:260001 of https://codereview.webrtc.org/2278883002/ )

Reason for revert:
Broke downstream application.

Original issue's description:
> Move MutableDataY{,U,V} methods to I420Buffer only.
> 
> Deleted from the VideoFrameBuffer base class.
> 
> BUG=webrtc:5921
> 
> Committed: https://crrev.com/5539ef6c03c273f39fadae41ace47fdc11ac6d60
> Cr-Commit-Position: refs/heads/master@{#14317}

TBR=perkj@webrtc.org,magjed@webrtc.org,pthatcher@webrtc.org,honghaiz@webrtc.o...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5921
==========

to

==========
Revert of Move MutableDataY{,U,V} methods to I420Buffer only. (patchset #14
id:260001 of https://codereview.webrtc.org/2278883002/ )

Reason for revert:
Broke downstream application.

Original issue's description:
> Move MutableDataY{,U,V} methods to I420Buffer only.
>
> Deleted from the VideoFrameBuffer base class.
>
> BUG=webrtc:5921
>
> Committed: https://crrev.com/5539ef6c03c273f39fadae41ace47fdc11ac6d60
> Cr-Commit-Position: refs/heads/master@{#14317}

TBR=perkj@webrtc.org,magjed@webrtc.org,pthatcher@webrtc.org,honghaiz@webrtc.o...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5921

Committed: https://crrev.com/776870a2599b8f43ad56987f9031690e3ccecde8
Cr-Commit-Position: refs/heads/master@{#14325}
==========

[commit-bot: I haz the power, 2016-09-21 10:52:25]

Patchset 1 (id:??) landed as
https://crrev.com/776870a2599b8f43ad56987f9031690e3ccecde8
Cr-Commit-Position: refs/heads/master@{#14325}

[nisse-webrtc, 2016-09-26 06:56:57]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.webrtc.org/2372483002/ by nisse@webrtc.org.

The reason for reverting is: Downstream application now fixed..