Revert of Switch BrowserAccessibilityStateImpl to the TaskScheduler API.

Revert of Switch BrowserAccessibilityStateImpl to the TaskScheduler API. (patchset #3 id:40001 of https://codereview.chromium.org/2888773002/ )

Reason for revert:
This is causing some issues on ChromeOS.

See crbug.com/725247

Original issue's description:
> Switch BrowserAccessibilityStateImpl to the TaskScheduler API.
> 
> It doesn't look like the #if defined(OS_WIN) block is necessary here, everything could be handled by the task scheduler directly.
> 
> BUG=689520
> 
> Review-Url: https://codereview.chromium.org/2888773002
> Cr-Commit-Position: refs/heads/master@{#473281}
> Committed: https://chromium.googlesource.com/chromium/src/+/1e0346d1ef0851ad07bf00fafefdd747bf30baed

TBR=dmazzoni@chromium.org,fdoray@chromium.org,aboxhall@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=689520
Review-Url: https://codereview.chromium.org/2899623003
Cr-Commit-Position: refs/heads/master@{#473777}
Committed: https://chromium.googlesource.com/chromium/src/+/4c535159fa525e13b5e41282be4e99c5b62149e7

[Sébastien Marchand, 2017-05-23 00:41:53]

The CQ bit was checked by sebmarchand@chromium.org

[Sébastien Marchand, 2017-05-23 00:41:53]

Created Revert of Switch BrowserAccessibilityStateImpl to the TaskScheduler API.

[commit-bot: I haz the power, 2017-05-23 00:42:37]

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, 2017-05-23 01:38:36]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495500113520190, "parent_rev":
"6b53c67659b98f640f9a50f54599ca90150eab18", "commit_rev":
"4c535159fa525e13b5e41282be4e99c5b62149e7"}

[commit-bot: I haz the power, 2017-05-23 01:38:48]

Description was changed from

==========
Revert of Switch BrowserAccessibilityStateImpl to the TaskScheduler API.
(patchset #3 id:40001 of https://codereview.chromium.org/2888773002/ )

Reason for revert:
This is causing some issues on ChromeOS.

See crbug.com/725247

Original issue's description:
> Switch BrowserAccessibilityStateImpl to the TaskScheduler API.
> 
> It doesn't look like the #if defined(OS_WIN) block is necessary here,
everything could be handled by the task scheduler directly.
> 
> BUG=689520
> 
> Review-Url: https://codereview.chromium.org/2888773002
> Cr-Commit-Position: refs/heads/master@{#473281}
> Committed:
https://chromium.googlesource.com/chromium/src/+/1e0346d1ef0851ad07bf00fafefd...

TBR=dmazzoni@chromium.org,fdoray@chromium.org,aboxhall@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=689520
==========

to

==========
Revert of Switch BrowserAccessibilityStateImpl to the TaskScheduler API.
(patchset #3 id:40001 of https://codereview.chromium.org/2888773002/ )

Reason for revert:
This is causing some issues on ChromeOS.

See crbug.com/725247

Original issue's description:
> Switch BrowserAccessibilityStateImpl to the TaskScheduler API.
> 
> It doesn't look like the #if defined(OS_WIN) block is necessary here,
everything could be handled by the task scheduler directly.
> 
> BUG=689520
> 
> Review-Url: https://codereview.chromium.org/2888773002
> Cr-Commit-Position: refs/heads/master@{#473281}
> Committed:
https://chromium.googlesource.com/chromium/src/+/1e0346d1ef0851ad07bf00fafefd...

TBR=dmazzoni@chromium.org,fdoray@chromium.org,aboxhall@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=689520

Review-Url: https://codereview.chromium.org/2899623003
Cr-Commit-Position: refs/heads/master@{#473777}
Committed:
https://chromium.googlesource.com/chromium/src/+/4c535159fa525e13b5e41282be4e...
==========

[commit-bot: I haz the power, 2017-05-23 01:38:56]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/4c535159fa525e13b5e41282be4e...