Revert of Add _decoder CHECK to VCMGenericDecoder constructor.

Revert of Add _decoder CHECK to VCMGenericDecoder constructor. (patchset #2 id:20001 of https://codereview.webrtc.org/1485713002/ )

Reason for revert:
Speculative revert since a downstream test started failing with this.

Original issue's description:
> Add _decoder CHECK to VCMGenericDecoder constructor.
>
> This should never be using a null decoder, but it looks like it's
> crashing out in the field. Adding a CHECK to see if it catches any
> interesting stack traces.
>
> Also making the _decoder pointer const to show that it should never be
> changing.
>
> BUG=chromium:563299
> R=stefan@webrtc.org
>
> Committed: https://chromium.googlesource.com/external/webrtc/+/a443ec1a75d10be0f24fa0163f23e1555d4c53cf

TBR=stefan@webrtc.org,pbos@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:563299
Committed: https://crrev.com/ec192bdb64d689415c34b74e10fc7859404abbf4
Cr-Commit-Position: refs/heads/master@{#10851}

[kjellander_webrtc, 2015-12-01 07:14:24]

Created Revert of Add _decoder CHECK to VCMGenericDecoder constructor.

[commit-bot: I haz the power, 2015-12-01 07:14:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1490703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1490703002/1

[commit-bot: I haz the power, 2015-12-01 07:14:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-01 07:14:44]

Description was changed from

==========
Revert of Add _decoder CHECK to VCMGenericDecoder constructor. (patchset #2
id:20001 of https://codereview.webrtc.org/1485713002/ )

Reason for revert:
Speculative revert since a downstream test started failing with this.

Original issue's description:
> Add _decoder CHECK to VCMGenericDecoder constructor.
> 
> This should never be using a null decoder, but it looks like it's
> crashing out in the field. Adding a CHECK to see if it catches any
> interesting stack traces.
> 
> Also making the _decoder pointer const to show that it should never be
> changing.
> 
> BUG=chromium:563299
> R=stefan@webrtc.org
> 
> Committed:
https://chromium.googlesource.com/external/webrtc/+/a443ec1a75d10be0f24fa0163...

TBR=stefan@webrtc.org,pbos@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:563299
==========

to

==========
Revert of Add _decoder CHECK to VCMGenericDecoder constructor. (patchset #2
id:20001 of https://codereview.webrtc.org/1485713002/ )

Reason for revert:
Speculative revert since a downstream test started failing with this.

Original issue's description:
> Add _decoder CHECK to VCMGenericDecoder constructor.
>
> This should never be using a null decoder, but it looks like it's
> crashing out in the field. Adding a CHECK to see if it catches any
> interesting stack traces.
>
> Also making the _decoder pointer const to show that it should never be
> changing.
>
> BUG=chromium:563299
> R=stefan@webrtc.org
>
> Committed:
https://chromium.googlesource.com/external/webrtc/+/a443ec1a75d10be0f24fa0163...

TBR=stefan@webrtc.org,pbos@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:563299

Committed: https://crrev.com/ec192bdb64d689415c34b74e10fc7859404abbf4
Cr-Commit-Position: refs/heads/master@{#10851}
==========

[commit-bot: I haz the power, 2015-12-01 07:14:45]

Patchset 1 (id:??) landed as
https://crrev.com/ec192bdb64d689415c34b74e10fc7859404abbf4
Cr-Commit-Position: refs/heads/master@{#10851}

[kjellander_webrtc, 2015-12-01 07:53:23]

On 2015/12/01 07:14:45, commit-bot: I haz the power wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/ec192bdb64d689415c34b74e10fc7859404abbf4
> Cr-Commit-Position: refs/heads/master@{#10851}

This revert helped, and all those tests are green again.