TaskScheduler: Fix initial order of SchedulerWorkers on idle stack.

TaskScheduler: Fix initial order of SchedulerWorkers on idle stack.

With this CL, SchedulerWorkers are pushed to the idle stack in
reverse order of index. This is nice for 2 reasons:
- In chrome://tracing, we see that workers with low indexes start
  running tasks before workers with high indexes.
- In chrome://tracing, if |Number of used workers| is less than
  |Max workers|, we see tracks for workers
  [0, Number of used workers - 1] rather than
  [Max workers - Number of used workers, Max workers - 1].

BUG=553459
Committed: https://crrev.com/ffe700619a9cffa614ed1424452cf1d7dba50206
Cr-Commit-Position: refs/heads/master@{#425167}

[fdoray, 2016-10-13 15:26:33]

fdoray@chromium.org changed reviewers:
+ robliao@chromium.org

[fdoray, 2016-10-13 15:26:34]

PTAL

[robliao, 2016-10-13 17:42:51]

lgtm

[fdoray, 2016-10-13 20:14:08]

The CQ bit was checked by fdoray@chromium.org

[commit-bot: I haz the power, 2016-10-13 20:14:32]

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, 2016-10-13 21:28:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-13 21:31:12]

Description was changed from

==========
TaskScheduler: Fix initial order of SchedulerWorkers on idle stack.

With this CL, SchedulerWorkers are pushed to the idle stack in
reverse order of index. This is nice for 2 reasons:
- In chrome://tracing, we see that workers with low indexes start
  running tasks before workers with high indexes.
- In chrome://tracing, if |Number of used workers| is less than
  |Max workers|, we see tracks for workers
  [0, Number of used workers - 1] rather than
  [Max workers - Number of used workers, Max workers - 1].

BUG=553459
==========

to

==========
TaskScheduler: Fix initial order of SchedulerWorkers on idle stack.

With this CL, SchedulerWorkers are pushed to the idle stack in
reverse order of index. This is nice for 2 reasons:
- In chrome://tracing, we see that workers with low indexes start
  running tasks before workers with high indexes.
- In chrome://tracing, if |Number of used workers| is less than
  |Max workers|, we see tracks for workers
  [0, Number of used workers - 1] rather than
  [Max workers - Number of used workers, Max workers - 1].

BUG=553459

Committed: https://crrev.com/ffe700619a9cffa614ed1424452cf1d7dba50206
Cr-Commit-Position: refs/heads/master@{#425167}
==========

[commit-bot: I haz the power, 2016-10-13 21:31:13]

Patchset 1 (id:??) landed as
https://crrev.com/ffe700619a9cffa614ed1424452cf1d7dba50206
Cr-Commit-Position: refs/heads/master@{#425167}

[gab, 2016-10-17 17:00:38]

gab@chromium.org changed reviewers:
+ gab@chromium.org

[gab, 2016-10-17 17:00:39]

Sweet, lgtm