Remove media sinks from Channel.

Remove media sinks from Channel.

Allows removing MediaRecorder which isn't in use apart from channel
unittests, along with it unittests for MediaRecorder that are flaky when
run in parallel can also go.

BUG=
R=pthatcher@webrtc.org

Committed: https://crrev.com/3b1e647b6a6f74d8e4392e012fe2262b3d2c4334
Cr-Commit-Position: refs/heads/master@{#9558}

[pbos-webrtc, 2015-07-02 14:49:25]

Hey Peter, am I allowed to delete some code? :)

[pbos-webrtc, 2015-07-02 14:49:29]

The CQ bit was checked by pbos@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-02 14:49:36]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219663008/1

[commit-bot: I haz the power, 2015-07-02 16:36:38]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-02 16:36:39]

Dry run: This issue passed the CQ dry run.

[pthatcher1, 2015-07-08 18:10:45]

lgtm

[pthatcher1, 2015-07-08 18:10:47]

lgtm

[pbos-webrtc, 2015-07-09 09:43:56]

The CQ bit was checked by pbos@webrtc.org

[commit-bot: I haz the power, 2015-07-09 09:44:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219663008/1

[commit-bot: I haz the power, 2015-07-09 09:44:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-09 09:44:11]

No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[tommi, 2015-07-09 09:57:36]

tommi@webrtc.org changed reviewers:
+ tommi@webrtc.org

[tommi, 2015-07-09 09:57:36]

Rs lgtm

[pbos-webrtc, 2015-07-09 09:58:16]

The CQ bit was checked by pbos@webrtc.org

[commit-bot: I haz the power, 2015-07-09 09:58:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219663008/1

[commit-bot: I haz the power, 2015-07-09 10:57:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-09 10:58:07]

Patchset 1 (id:??) landed as
https://crrev.com/3b1e647b6a6f74d8e4392e012fe2262b3d2c4334
Cr-Commit-Position: refs/heads/master@{#9558}

[phoglund, 2015-07-09 10:58:37]

On 2015/07/09 09:58:30, commit-bot: I haz the power wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1219663008/1

There was a typo in the committer list for pthatcher, so I'm fixing that with
https://chromereviews.googleplex.com/226687013.

[pbos-webrtc, 2015-07-09 12:07:56]

On 2015/07/09 10:58:37, phoglund wrote:
> On 2015/07/09 09:58:30, commit-bot: I haz the power wrote:
> > CQ is trying da patch. Follow status at
> >  https://chromium-cq-status.appspot.com/patch-status/1219663008/1
> 
> There was a typo in the committer list for pthatcher, so I'm fixing that with
> https://chromereviews.googleplex.com/226687013.

thx :)