Use TaskScheduler instead of blocking pool in download_target_determiner.cc.

Use TaskScheduler instead of blocking pool in download_target_determiner.cc.

The following traits are used:

Priority: Inherited (default)
  The priority is inherited from the calling context (i.e. TaskTraits
  are initialized with the priority of the current task).

Shutdown behavior: SKIP_ON_SHUTDOWN (default)
  Tasks posted with this mode that have not started executing at
  shutdown will never run. However, any task that has already begun
  executing when shutdown is invoked will be allowed to continue and
  will block shutdown until completion.

  Note: Previously, the task was posted to the blocking pool with
  BLOCK_SHUTDOWN (default in SequencedWorkerPool).

May Block:
  Tasks posted with MayBlock() may block. This includes but is not
  limited to tasks that wait on synchronous file I/O operations:
  read or write a file from disk, interact with a pipe or a socket,
  rename or delete a file, enumerate files in a directory, etc. This
  trait isn't required for the mere use of locks.

BUG=667892
Review-Url: https://codereview.chromium.org/2625193002
Cr-Commit-Position: refs/heads/master@{#443232}
Committed: https://chromium.googlesource.com/chromium/src/+/5cb986a6e5de91c01793068fdf8801900a0bd9bd

[fdoray, 2017-01-11 21:39:01]

The CQ bit was checked by fdoray@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-11 21:39:38]

Dry run: 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, 2017-01-11 22:35:02]

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

[commit-bot: I haz the power, 2017-01-11 22:35:02]

Dry run: This issue passed the CQ dry run.

[fdoray, 2017-01-12 13:26:38]

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

[fdoray, 2017-01-12 13:26:38]

PTAL

Blocking pool is being deprecated in favor of TaskScheduler.

[asanka, 2017-01-12 15:00:51]

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

[asanka, 2017-01-12 15:00:51]

lgtm

The the SKIP_ON_SHUTDOWN behavior is correct in this case. The task is being
used to query the state of the Adobe Reader plugin. The result would be unusable
if the browser is being shut down since the download and the filename
determination operation won't be able to make progress. The download will become
interrupted without a database update. The DownloadItem destruction should take
care of the temporary file if the FILE thread is still operational.

[fdoray, 2017-01-12 15:08:34]

The CQ bit was checked by fdoray@chromium.org

[commit-bot: I haz the power, 2017-01-12 15:08:52]

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, 2017-01-12 15:13:52]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1484233714421440, "parent_rev":
"d5cf623f025f2d8e54cd9e029f4340dd49b7dc81", "commit_rev":
"5cb986a6e5de91c01793068fdf8801900a0bd9bd"}

[commit-bot: I haz the power, 2017-01-12 15:14:30]

Description was changed from

==========
Use TaskScheduler instead of blocking pool in download_target_determiner.cc.

The following traits are used:

Priority: Inherited (default)
  The priority is inherited from the calling context (i.e. TaskTraits
  are initialized with the priority of the current task).

Shutdown behavior: SKIP_ON_SHUTDOWN (default)
  Tasks posted with this mode that have not started executing at
  shutdown will never run. However, any task that has already begun
  executing when shutdown is invoked will be allowed to continue and
  will block shutdown until completion.

  Note: Previously, the task was posted to the blocking pool with
  BLOCK_SHUTDOWN (default in SequencedWorkerPool).

May Block:
  Tasks posted with MayBlock() may block. This includes but is not
  limited to tasks that wait on synchronous file I/O operations:
  read or write a file from disk, interact with a pipe or a socket,
  rename or delete a file, enumerate files in a directory, etc. This
  trait isn't required for the mere use of locks.

BUG=667892
==========

to

==========
Use TaskScheduler instead of blocking pool in download_target_determiner.cc.

The following traits are used:

Priority: Inherited (default)
  The priority is inherited from the calling context (i.e. TaskTraits
  are initialized with the priority of the current task).

Shutdown behavior: SKIP_ON_SHUTDOWN (default)
  Tasks posted with this mode that have not started executing at
  shutdown will never run. However, any task that has already begun
  executing when shutdown is invoked will be allowed to continue and
  will block shutdown until completion.

  Note: Previously, the task was posted to the blocking pool with
  BLOCK_SHUTDOWN (default in SequencedWorkerPool).

May Block:
  Tasks posted with MayBlock() may block. This includes but is not
  limited to tasks that wait on synchronous file I/O operations:
  read or write a file from disk, interact with a pipe or a socket,
  rename or delete a file, enumerate files in a directory, etc. This
  trait isn't required for the mere use of locks.

BUG=667892

Review-Url: https://codereview.chromium.org/2625193002
Cr-Commit-Position: refs/heads/master@{#443232}
Committed:
https://chromium.googlesource.com/chromium/src/+/5cb986a6e5de91c01793068fdf88...
==========

[commit-bot: I haz the power, 2017-01-12 15:14:31]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/5cb986a6e5de91c01793068fdf88...