Add base::test::ScopedTaskEnvironment.

Add base::test::ScopedTaskEnvironment.

ScopedTaskEnvironment allows usage of these APIs within its scope:
- ThreadTaskRunnerHandle, on the thread where it lives
- base/task_scheduler/post_task.h, on any thread

Tests that need either of these APIs should instantiate a
ScopedTaskEnvironment.

Design doc
https://docs.google.com/document/d/1QabRo8c7D9LsYY3cEcaPQbOCLo8Tu-6VLykYXyl3Pkk/edit

BUG=708584
Review-Url: https://codereview.chromium.org/2796403002
Cr-Commit-Position: refs/heads/master@{#462477}
Committed: https://chromium.googlesource.com/chromium/src/+/a1f53b7c3cca3156dcf7cd7a57264d888ea318ef

[fdoray, 2017-04-05 15:04:05]

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

[commit-bot: I haz the power, 2017-04-05 15:04:45]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[fdoray, 2017-04-05 15:05:38]

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

[fdoray, 2017-04-05 15:05:39]

PTAL

Notes:
- I document that ScopedTaskEnvironment provides a ThreadTaskRunnerHandle, not a
MessageLoop. This is because MessageLoop will be deprecated in favor of
TaskScheduler main thread scheduling.
- Mock time and flushing all tasks are not implemented nor documented in this
CL.

[fdoray, 2017-04-05 15:06:45]

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

[commit-bot: I haz the power, 2017-04-05 15:07:09]

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, 2017-04-05 16:36:31]

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

[commit-bot: I haz the power, 2017-04-05 16:36:32]

Dry run: This issue passed the CQ dry run.

[gab, 2017-04-05 20:44:24]

lgtm w/ comments, thanks!

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_async_...
File base/test/scoped_async_task_scheduler.h (right):

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_async_...
base/test/scoped_async_task_scheduler.h:21: // Deprecated. Use
ScopedTaskEnvironment instead. https://crbug.com/708584
TODO(fdoray): Replace ScopedAsyncTaskScheduler instances by
ScopedTaskEnvironment.

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
File base/test/scoped_task_environment.h (right):

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
base/test/scoped_task_environment.h:18: // - ThreadTaskRunnerHandle, on the
thread where it lives
(Thread|Sequenced)TaskRunnerHandle

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
base/test/scoped_task_environment.h:31: // Future improvements documented in:
// Design and future improvements documented in

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
base/test/scoped_task_environment.h:43: MessageLoop message_loop_;
// Note: |message_loop_| is an implementation detail and will be replaced in the
future, do NOT rely on the presence of a MessageLoop beyond
ThreadTaskRunnerHandle and RunLoop.

[gab, 2017-04-05 20:44:42]

Also link to doc from CL desc.

[fdoray, 2017-04-06 13:58:07]

Description was changed from

==========
Add base::test::ScopedTaskEnvironment.

ScopedTaskEnvironment allows usage of these APIs within its scope:
- ThreadTaskRunnerHandle, on the thread where it lives
- base/task_scheduler/post_task.h, on any thread

Tests that need either of these APIs should instantiate a
ScopedTaskEnvironment.

BUG=708584
==========

to

==========
Add base::test::ScopedTaskEnvironment.

ScopedTaskEnvironment allows usage of these APIs within its scope:
- ThreadTaskRunnerHandle, on the thread where it lives
- base/task_scheduler/post_task.h, on any thread

Tests that need either of these APIs should instantiate a
ScopedTaskEnvironment.

Design doc
https://docs.google.com/document/d/1QabRo8c7D9LsYY3cEcaPQbOCLo8Tu-6VLykYXyl3P...

BUG=708584
==========

[fdoray, 2017-04-06 14:00:08]

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

[fdoray, 2017-04-06 14:00:14]

The CQ bit was unchecked by fdoray@chromium.org

[fdoray, 2017-04-06 14:00:18]

The CQ bit was checked by fdoray@chromium.org

[fdoray, 2017-04-06 14:00:18]

The patchset sent to the CQ was uploaded after l-g-t-m from gab@chromium.org
Link to the patchset: https://codereview.chromium.org/2796403002/#ps60001
(title: "CR-gab-9")

[fdoray, 2017-04-06 14:00:23]

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_async_...
File base/test/scoped_async_task_scheduler.h (right):

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_async_...
base/test/scoped_async_task_scheduler.h:21: // Deprecated. Use
ScopedTaskEnvironment instead. https://crbug.com/708584
On 2017/04/05 20:44:24, gab wrote:
> TODO(fdoray): Replace ScopedAsyncTaskScheduler instances by
> ScopedTaskEnvironment.

Done.

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
File base/test/scoped_task_environment.h (right):

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
base/test/scoped_task_environment.h:18: // - ThreadTaskRunnerHandle, on the
thread where it lives
On 2017/04/05 20:44:24, gab wrote:
> (Thread|Sequenced)TaskRunnerHandle

Done.

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
base/test/scoped_task_environment.h:31: // Future improvements documented in:
On 2017/04/05 20:44:24, gab wrote:
> // Design and future improvements documented in

Done.

https://codereview.chromium.org/2796403002/diff/40001/base/test/scoped_task_e...
base/test/scoped_task_environment.h:43: MessageLoop message_loop_;
On 2017/04/05 20:44:24, gab wrote:
> // Note: |message_loop_| is an implementation detail and will be replaced in
the
> future, do NOT rely on the presence of a MessageLoop beyond
> ThreadTaskRunnerHandle and RunLoop.

Done.

[commit-bot: I haz the power, 2017-04-06 14:00:29]

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, 2017-04-06 15:17:03]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1491487218060010,
"parent_rev": "7ce21e2df98546eb664d6cbcd11a592d1599dd48", "commit_rev":
"a1f53b7c3cca3156dcf7cd7a57264d888ea318ef"}

[commit-bot: I haz the power, 2017-04-06 15:17:55]

Description was changed from

==========
Add base::test::ScopedTaskEnvironment.

ScopedTaskEnvironment allows usage of these APIs within its scope:
- ThreadTaskRunnerHandle, on the thread where it lives
- base/task_scheduler/post_task.h, on any thread

Tests that need either of these APIs should instantiate a
ScopedTaskEnvironment.

Design doc
https://docs.google.com/document/d/1QabRo8c7D9LsYY3cEcaPQbOCLo8Tu-6VLykYXyl3P...

BUG=708584
==========

to

==========
Add base::test::ScopedTaskEnvironment.

ScopedTaskEnvironment allows usage of these APIs within its scope:
- ThreadTaskRunnerHandle, on the thread where it lives
- base/task_scheduler/post_task.h, on any thread

Tests that need either of these APIs should instantiate a
ScopedTaskEnvironment.

Design doc
https://docs.google.com/document/d/1QabRo8c7D9LsYY3cEcaPQbOCLo8Tu-6VLykYXyl3P...

BUG=708584

Review-Url: https://codereview.chromium.org/2796403002
Cr-Commit-Position: refs/heads/master@{#462477}
Committed:
https://chromium.googlesource.com/chromium/src/+/a1f53b7c3cca3156dcf7cd7a5726...
==========

[commit-bot: I haz the power, 2017-04-06 15:17:56]

Committed patchset #4 (id:60001) as
https://chromium.googlesource.com/chromium/src/+/a1f53b7c3cca3156dcf7cd7a5726...