VideoProcessor: make it runnable on a task queue.

VideoProcessor: make it runnable on a task queue.

* Guard members with a SequencedTaskChecker.
* Intercept encoder/decoder callbacks, and post onto task queue if needed.

BUG=webrtc:6634
Review-Url: https://codereview.webrtc.org/2996253002
Cr-Commit-Position: refs/heads/master@{#19428}
Committed: https://chromium.googlesource.com/external/webrtc/+/c8c59059b74d6e093dd86902ada98eba587d984a

[brandtr, 2017-08-18 13:57:58]

brandtr@webrtc.org changed reviewers:
+ asapersson@webrtc.org

[brandtr, 2017-08-18 13:57:58]

Split up the mega-CL in several smaller ones, for easier review :) The first
three are just mini-fixes, the 4th CL will contain the actual important stuff.

[åsapersson, 2017-08-21 11:39:12]

lgtm

[brandtr, 2017-08-21 11:57:08]

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

[commit-bot: I haz the power, 2017-08-21 11:57:14]

Dry run: 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, 2017-08-21 13:25:04]

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

[commit-bot: I haz the power, 2017-08-21 13:25:04]

Dry run: This issue passed the CQ dry run.

[brandtr, 2017-08-21 13:41:50]

The CQ bit was checked by brandtr@webrtc.org

[commit-bot: I haz the power, 2017-08-21 13:41:56]

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, 2017-08-21 13:44:16]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1503322910645870, "parent_rev":
"e57556c764b30c03ab7da3c5fee56cf105306dd6", "commit_rev":
"c8c59059b74d6e093dd86902ada98eba587d984a"}

[commit-bot: I haz the power, 2017-08-21 13:44:23]

Description was changed from

==========
VideoProcessor: make it runnable on a task queue.

* Guard members with a SequencedTaskChecker.
* Intercept encoder/decoder callbacks, and post onto task queue if needed.

BUG=webrtc:6634
==========

to

==========
VideoProcessor: make it runnable on a task queue.

* Guard members with a SequencedTaskChecker.
* Intercept encoder/decoder callbacks, and post onto task queue if needed.

BUG=webrtc:6634

Review-Url: https://codereview.webrtc.org/2996253002
Cr-Commit-Position: refs/heads/master@{#19428}
Committed:
https://chromium.googlesource.com/external/webrtc/+/c8c59059b74d6e093dd86902a...
==========

[commit-bot: I haz the power, 2017-08-21 13:44:24]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/c8c59059b74d6e093dd86902a...