Revert of Use SequenceChecker to allow Timer to run in SequencedWorkerPool

Revert of Use SequenceChecker to allow Timer to run in SequencedWorkerPool (patchset #6 id:100001 of https://codereview.chromium.org/1433373003/ )

Reason for revert:
TSAN failures in the test. Won't have a chance to debug for a few days, so reverting for now.

Sample failure:

https://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20TSan%20Tests/builds/14813

Original issue's description:
> Use SequenceChecker to allow Timer to run in SequencedWorkerPool
>
> Timer was explicitly ensuring single-threaded usage by tracking the
> thread used for scheduling tasks. Generalize that to ensure sequenced
> task runner affinity via SequenceChecker, so it can be used by
> SequencedWorkerPool threads.
>
> BUG=552633
>
> Committed: https://crrev.com/ffa30fe7f5ec8b13c9e41d41d828e4fb8e67110b
> Cr-Commit-Position: refs/heads/master@{#365568}

TBR=gab@chromium.org,danakj@chromium.org,thakis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=552633
Committed: https://crrev.com/763cd405e2c86701be08e3e64a24df6a2e316e7f
Cr-Commit-Position: refs/heads/master@{#365683}

[jsbell, 2015-12-17 00:04:09]

Created Revert of Use SequenceChecker to allow Timer to run in
SequencedWorkerPool

[commit-bot: I haz the power, 2015-12-17 00:06:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1532773002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1532773002/1

[commit-bot: I haz the power, 2015-12-17 00:11:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1532773002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1532773002/1

[commit-bot: I haz the power, 2015-12-17 00:33:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1532773002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1532773002/1

[commit-bot: I haz the power, 2015-12-17 00:38:36]

Description was changed from

==========
Revert of Use SequenceChecker to allow Timer to run in SequencedWorkerPool
(patchset #6 id:100001 of https://codereview.chromium.org/1433373003/ )

Reason for revert:
TSAN failures in the test. Won't have a chance to debug for a few days, so
reverting for now.

Sample failure:

https://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20TSan%20Test...

Original issue's description:
> Use SequenceChecker to allow Timer to run in SequencedWorkerPool
> 
> Timer was explicitly ensuring single-threaded usage by tracking the
> thread used for scheduling tasks. Generalize that to ensure sequenced
> task runner affinity via SequenceChecker, so it can be used by
> SequencedWorkerPool threads.
> 
> BUG=552633
> 
> Committed: https://crrev.com/ffa30fe7f5ec8b13c9e41d41d828e4fb8e67110b
> Cr-Commit-Position: refs/heads/master@{#365568}

TBR=gab@chromium.org,danakj@chromium.org,thakis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=552633
==========

to

==========
Revert of Use SequenceChecker to allow Timer to run in SequencedWorkerPool
(patchset #6 id:100001 of https://codereview.chromium.org/1433373003/ )

Reason for revert:
TSAN failures in the test. Won't have a chance to debug for a few days, so
reverting for now.

Sample failure:

https://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20TSan%20Test...

Original issue's description:
> Use SequenceChecker to allow Timer to run in SequencedWorkerPool
> 
> Timer was explicitly ensuring single-threaded usage by tracking the
> thread used for scheduling tasks. Generalize that to ensure sequenced
> task runner affinity via SequenceChecker, so it can be used by
> SequencedWorkerPool threads.
> 
> BUG=552633
> 
> Committed: https://crrev.com/ffa30fe7f5ec8b13c9e41d41d828e4fb8e67110b
> Cr-Commit-Position: refs/heads/master@{#365568}

TBR=gab@chromium.org,danakj@chromium.org,thakis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=552633
==========

[commit-bot: I haz the power, 2015-12-17 00:38:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-17 00:39:37]

Description was changed from

==========
Revert of Use SequenceChecker to allow Timer to run in SequencedWorkerPool
(patchset #6 id:100001 of https://codereview.chromium.org/1433373003/ )

Reason for revert:
TSAN failures in the test. Won't have a chance to debug for a few days, so
reverting for now.

Sample failure:

https://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20TSan%20Test...

Original issue's description:
> Use SequenceChecker to allow Timer to run in SequencedWorkerPool
> 
> Timer was explicitly ensuring single-threaded usage by tracking the
> thread used for scheduling tasks. Generalize that to ensure sequenced
> task runner affinity via SequenceChecker, so it can be used by
> SequencedWorkerPool threads.
> 
> BUG=552633
> 
> Committed: https://crrev.com/ffa30fe7f5ec8b13c9e41d41d828e4fb8e67110b
> Cr-Commit-Position: refs/heads/master@{#365568}

TBR=gab@chromium.org,danakj@chromium.org,thakis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=552633
==========

to

==========
Revert of Use SequenceChecker to allow Timer to run in SequencedWorkerPool
(patchset #6 id:100001 of https://codereview.chromium.org/1433373003/ )

Reason for revert:
TSAN failures in the test. Won't have a chance to debug for a few days, so
reverting for now.

Sample failure:

https://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20TSan%20Test...

Original issue's description:
> Use SequenceChecker to allow Timer to run in SequencedWorkerPool
>
> Timer was explicitly ensuring single-threaded usage by tracking the
> thread used for scheduling tasks. Generalize that to ensure sequenced
> task runner affinity via SequenceChecker, so it can be used by
> SequencedWorkerPool threads.
>
> BUG=552633
>
> Committed: https://crrev.com/ffa30fe7f5ec8b13c9e41d41d828e4fb8e67110b
> Cr-Commit-Position: refs/heads/master@{#365568}

TBR=gab@chromium.org,danakj@chromium.org,thakis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=552633

Committed: https://crrev.com/763cd405e2c86701be08e3e64a24df6a2e316e7f
Cr-Commit-Position: refs/heads/master@{#365683}
==========

[commit-bot: I haz the power, 2015-12-17 00:39:38]

Patchset 1 (id:??) landed as
https://crrev.com/763cd405e2c86701be08e3e64a24df6a2e316e7f
Cr-Commit-Position: refs/heads/master@{#365683}