Revert of Add support for converting I420 software frames into NV12 hardware frames

Revert of Add support for converting I420 software frames into NV12 hardware frames (patchset #6 id:140001 of https://codereview.chromium.org/1307853003/ )

Reason for revert:
We suspect this CL caused a WebRTC browser test to start failing.

The failures are consistent and started here:
https://build.chromium.org/p/chromium.webrtc/builders/Win7%20Tester/builds/21330

Original issue's description:
> Add support for converting I420 software frames into NV12 hardware frames
>
> Enhance MaybeCreateHardwareFrame() to be able to create a NV12 hardware
> frame backed by a YUV_420_BIPLANAR GpuMemoryBuffer.
>
> This code path is not enabled yet.
>
> BUG=524582
> CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/422d099ed5b8439b92d198deb84d4528c14ccc0c
> Cr-Commit-Position: refs/heads/master@{#347864}

TBR=dcastagna@chromium.org,sandersd@chromium.org,ccameron@chromium.org,andresantoso@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=524582
Committed: https://crrev.com/9fbd81e3c8adf06f9a77d917050eb99f2cdad3c3
Cr-Commit-Position: refs/heads/master@{#348120}

[tommi (sloooow) - chröme, 2015-09-10 08:54:06]

Created Revert of Add support for converting I420 software frames into NV12
hardware frames

[commit-bot: I haz the power, 2015-09-10 08:54:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1327243002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1327243002/1

[tommi (sloooow) - chröme, 2015-09-10 08:54:25]

tommi@chromium.org changed reviewers:
+ guidou@chromium.org

[tommi (sloooow) - chröme, 2015-09-10 08:54:26]

+webrtc sheriff

[commit-bot: I haz the power, 2015-09-10 08:54:51]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-10 08:55:43]

Patchset 1 (id:??) landed as
https://crrev.com/9fbd81e3c8adf06f9a77d917050eb99f2cdad3c3
Cr-Commit-Position: refs/heads/master@{#348120}

[commit-bot: I haz the power, 2015-09-23 12:08:51]

Patchset 1 (id:??) landed as
https://crrev.com/9fbd81e3c8adf06f9a77d917050eb99f2cdad3c3
Cr-Commit-Position: refs/heads/master@{#348120}