Revert of Reuse allocated encoders in SimulcastEncoderAdapter.

Revert of Reuse allocated encoders in SimulcastEncoderAdapter. (patchset #15 id:320001 of https://codereview.webrtc.org/2830793005/ )

Reason for revert:
Breaks Chrome tests.

Original issue's description:
> Reuse allocated encoders in SimulcastEncoderAdapter.
> 
> Prior to this change, the SimulcastEncoderAdapter would destroy and create
> encoders whenever it is being reinitialized. After this change, the
> SimulcastEncoderAdapter will cache the already allocated encoders, and reuse
> them after reinitialization.
> 
> This change will help in reducing the number of PictureID "jumps" that have
> been seen around encoder reinitialization.
> 
> TESTED=AppRTCMobile, Chrome desktop, and internal app, with forced encoder reinits every 30 frames and https://codereview.webrtc.org/2833493003/ applied.
> BUG=webrtc:7475
> 
> Review-Url: https://codereview.webrtc.org/2830793005
> Cr-Commit-Position: refs/heads/master@{#18215}
> Committed: https://chromium.googlesource.com/external/webrtc/+/0b8bfb9d98b7a2011d80bcdf3f430bc040370dad

TBR=stefan@webrtc.org,noahric@chromium.org,glaznev@webrtc.org,sprang@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7475
Review-Url: https://codereview.webrtc.org/2893003002
Cr-Commit-Position: refs/heads/master@{#18216}
Committed: https://chromium.googlesource.com/external/webrtc/+/56e119e2e8b30d2d41c55c3a7983b077a5262718

[brandtr, 2017-05-19 17:32:54]

The CQ bit was checked by brandtr@webrtc.org

[brandtr, 2017-05-19 17:32:54]

Created Revert of Reuse allocated encoders in SimulcastEncoderAdapter.

[commit-bot: I haz the power, 2017-05-19 17:32:57]

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, 2017-05-19 17:33:03]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495215174183040, "parent_rev":
"0b8bfb9d98b7a2011d80bcdf3f430bc040370dad", "commit_rev":
"56e119e2e8b30d2d41c55c3a7983b077a5262718"}

[commit-bot: I haz the power, 2017-05-19 17:33:09]

Description was changed from

==========
Revert of Reuse allocated encoders in SimulcastEncoderAdapter. (patchset #15
id:320001 of https://codereview.webrtc.org/2830793005/ )

Reason for revert:
Breaks Chrome tests.

Original issue's description:
> Reuse allocated encoders in SimulcastEncoderAdapter.
> 
> Prior to this change, the SimulcastEncoderAdapter would destroy and create
> encoders whenever it is being reinitialized. After this change, the
> SimulcastEncoderAdapter will cache the already allocated encoders, and reuse
> them after reinitialization.
> 
> This change will help in reducing the number of PictureID "jumps" that have
> been seen around encoder reinitialization.
> 
> TESTED=AppRTCMobile, Chrome desktop, and internal app, with forced encoder
reinits every 30 frames and https://codereview.webrtc.org/2833493003/ applied.
> BUG=webrtc:7475
> 
> Review-Url: https://codereview.webrtc.org/2830793005
> Cr-Commit-Position: refs/heads/master@{#18215}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/0b8bfb9d98b7a2011d80bcdf3...

TBR=stefan@webrtc.org,noahric@chromium.org,glaznev@webrtc.org,sprang@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7475
==========

to

==========
Revert of Reuse allocated encoders in SimulcastEncoderAdapter. (patchset #15
id:320001 of https://codereview.webrtc.org/2830793005/ )

Reason for revert:
Breaks Chrome tests.

Original issue's description:
> Reuse allocated encoders in SimulcastEncoderAdapter.
> 
> Prior to this change, the SimulcastEncoderAdapter would destroy and create
> encoders whenever it is being reinitialized. After this change, the
> SimulcastEncoderAdapter will cache the already allocated encoders, and reuse
> them after reinitialization.
> 
> This change will help in reducing the number of PictureID "jumps" that have
> been seen around encoder reinitialization.
> 
> TESTED=AppRTCMobile, Chrome desktop, and internal app, with forced encoder
reinits every 30 frames and https://codereview.webrtc.org/2833493003/ applied.
> BUG=webrtc:7475
> 
> Review-Url: https://codereview.webrtc.org/2830793005
> Cr-Commit-Position: refs/heads/master@{#18215}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/0b8bfb9d98b7a2011d80bcdf3...

TBR=stefan@webrtc.org,noahric@chromium.org,glaznev@webrtc.org,sprang@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7475

Review-Url: https://codereview.webrtc.org/2893003002
Cr-Commit-Position: refs/heads/master@{#18216}
Committed:
https://chromium.googlesource.com/external/webrtc/+/56e119e2e8b30d2d41c55c3a7...
==========

[commit-bot: I haz the power, 2017-05-19 17:33:10]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/56e119e2e8b30d2d41c55c3a7...

[brandtr, 2017-05-22 07:12:21]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.webrtc.org/2901493002/ by brandtr@webrtc.org.

The reason for reverting is: Don't call RegisterEncodeCallback(nullptr), to
satisfy test..