Revert of Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on trunk

Revert of Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on trunk (patchset #1 id:1 of https://codereview.chromium.org/2856583002/ )

Reason for revert:
Possible failure: https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.chromiumos%2FLinux_ChromiumOS_Tests__dbg__1_%2F25521%2F%2B%2Frecipes%2Fsteps%2Fbrowser_tests%2F0%2Flogs%2FCaptivePortalWindowTest.OnRedirected%2F0

Original issue's description:
> Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on trunk
>
> This reverts commit f07732ec0e39ad7e9f1ad279f2624dbdf261803d
> (https://codereview.chromium.org/2791933004)
> and reapplies b6d0c9a06ab573af760763fcd7ecf76ae2c87695
> (https://codereview.chromium.org/2690183002/).
>
> BUG=653916, 707986
> TBR=jam@chromium.org, rkaplow@chromium.org
> Previously reviewed at https://codereview.chromium.org/2690183002/
>
> Review-Url: https://codereview.chromium.org/2856583002
> Cr-Commit-Position: refs/heads/master@{#468376}
> Committed: https://chromium.googlesource.com/chromium/src/+/3e27cb6e501ae55d614b56d566487590518ec223

TBR=jam@chromium.org,rkaplow@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=653916, 707986
Review-Url: https://codereview.chromium.org/2848413002
Cr-Commit-Position: refs/heads/master@{#468481}
Committed: https://chromium.googlesource.com/chromium/src/+/d4be08b81e51bbf512152939dce9955133f74864

[robliao, 2017-05-01 23:31:41]

The CQ bit was checked by robliao@chromium.org

[robliao, 2017-05-01 23:31:41]

Created Revert of Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by
default on trunk

[commit-bot: I haz the power, 2017-05-01 23:32:14]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-01 23:32:39]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493681501377780, "parent_rev":
"abeb3b928b8834dd180f8b75ccca53b52d6cde55", "commit_rev":
"d4be08b81e51bbf512152939dce9955133f74864"}

[commit-bot: I haz the power, 2017-05-01 23:34:30]

Description was changed from

==========
Revert of Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on
trunk (patchset #1 id:1 of https://codereview.chromium.org/2856583002/ )

Reason for revert:
Possible failure:
https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.chromiumos%2FLi...

Original issue's description:
> Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on trunk
> 
> This reverts commit f07732ec0e39ad7e9f1ad279f2624dbdf261803d 
> (https://codereview.chromium.org/2791933004)
> and reapplies b6d0c9a06ab573af760763fcd7ecf76ae2c87695
> (https://codereview.chromium.org/2690183002/).
> 
> BUG=653916, 707986
> TBR=jam@chromium.org, rkaplow@chromium.org
> Previously reviewed at https://codereview.chromium.org/2690183002/
> 
> Review-Url: https://codereview.chromium.org/2856583002
> Cr-Commit-Position: refs/heads/master@{#468376}
> Committed:
https://chromium.googlesource.com/chromium/src/+/3e27cb6e501ae55d614b56d56648...

TBR=jam@chromium.org,rkaplow@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=653916, 707986
==========

to

==========
Revert of Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on
trunk (patchset #1 id:1 of https://codereview.chromium.org/2856583002/ )

Reason for revert:
Possible failure:
https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.chromiumos%2FLi...

Original issue's description:
> Reland RedirectNonUINonIOBrowserThreads to TaskScheduler by default on trunk
>
> This reverts commit f07732ec0e39ad7e9f1ad279f2624dbdf261803d
> (https://codereview.chromium.org/2791933004)
> and reapplies b6d0c9a06ab573af760763fcd7ecf76ae2c87695
> (https://codereview.chromium.org/2690183002/).
>
> BUG=653916, 707986
> TBR=jam@chromium.org, rkaplow@chromium.org
> Previously reviewed at https://codereview.chromium.org/2690183002/
>
> Review-Url: https://codereview.chromium.org/2856583002
> Cr-Commit-Position: refs/heads/master@{#468376}
> Committed:
https://chromium.googlesource.com/chromium/src/+/3e27cb6e501ae55d614b56d56648...

TBR=jam@chromium.org,rkaplow@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=653916, 707986

Review-Url: https://codereview.chromium.org/2848413002
Cr-Commit-Position: refs/heads/master@{#468481}
Committed:
https://chromium.googlesource.com/chromium/src/+/d4be08b81e51bbf512152939dce9...
==========

[commit-bot: I haz the power, 2017-05-01 23:34:30]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/d4be08b81e51bbf512152939dce9...