Use correct task traits for mojo leveldb env background tasks.

Use correct task traits for mojo leveldb env background tasks.

These background tasks can do file operations, which might involve
blocking using base::WaitableEvents as well as other blocking in
leveldb code itself.

BUG=697612
Review-Url: https://codereview.chromium.org/2838663002
Cr-Commit-Position: refs/heads/master@{#466786}
Committed: https://chromium.googlesource.com/chromium/src/+/9a16c13f62099154b115bf2e3464efb075b9d3f9

[Marijn Kruisselbrink, 2017-04-24 18:44:42]

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

[commit-bot: I haz the power, 2017-04-24 18:45:45]

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, 2017-04-24 19:58:32]

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

[commit-bot: I haz the power, 2017-04-24 19:58:33]

Dry run: This issue passed the CQ dry run.

[Marijn Kruisselbrink, 2017-04-24 20:27:32]

mek@chromium.org changed reviewers:
+ michaeln@chromium.org

[michaeln, 2017-04-24 20:54:18]

https://codereview.chromium.org/2838663002/diff/1/components/leveldb/env_mojo.cc
File components/leveldb/env_mojo.cc (right):

https://codereview.chromium.org/2838663002/diff/1/components/leveldb/env_mojo...
components/leveldb/env_mojo.cc:417: FROM_HERE,
base::TaskTraits().MayBlock().WithBaseSyncPrimitives(),
lgtm - Do you know if these tasks are skipped whether other 'threads' will wait
indefinitely? I'm wondering if they should also be
WithShutdownBehavior(BLOCK_SHUTDOWN) for that potential reason?

[Marijn Kruisselbrink, 2017-04-24 21:05:08]

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

[Marijn Kruisselbrink, 2017-04-24 21:05:23]

https://codereview.chromium.org/2838663002/diff/1/components/leveldb/env_mojo.cc
File components/leveldb/env_mojo.cc (right):

https://codereview.chromium.org/2838663002/diff/1/components/leveldb/env_mojo...
components/leveldb/env_mojo.cc:417: FROM_HERE,
base::TaskTraits().MayBlock().WithBaseSyncPrimitives(),
On 2017/04/24 at 20:54:17, michaeln wrote:
> lgtm - Do you know if these tasks are skipped whether other 'threads' will
wait indefinitely? I'm wondering if they should also be
WithShutdownBehavior(BLOCK_SHUTDOWN) for that potential reason?

Good point, yes, I believe destructing the leveldb::DBImpl instance could block
indefinitely if a background task was scheduled, but then not run because of
SKIP_ON_SHUTDOWN. Added the correct shutdown behavior.

[commit-bot: I haz the power, 2017-04-24 21:05:46]

Dry run: CQ is trying da patch.

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

[Marijn Kruisselbrink, 2017-04-24 21:53:43]

The CQ bit was unchecked by mek@chromium.org

[Marijn Kruisselbrink, 2017-04-24 21:53:45]

The CQ bit was checked by mek@chromium.org

[Marijn Kruisselbrink, 2017-04-24 21:53:45]

The patchset sent to the CQ was uploaded after l-g-t-m from
michaeln@chromium.org
Link to the patchset: https://codereview.chromium.org/2838663002/#ps20001
(title: "correct shutdown behavior")

[commit-bot: I haz the power, 2017-04-24 21:54:17]

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, 2017-04-24 22:04:07]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1493070825122710,
"parent_rev": "854dede8e4cb7885e803e9e7f3223f00e89a6d38", "commit_rev":
"9a16c13f62099154b115bf2e3464efb075b9d3f9"}

[commit-bot: I haz the power, 2017-04-24 22:04:23]

Description was changed from

==========
Use correct task traits for mojo leveldb env background tasks.

These background tasks can do file operations, which might involve
blocking using base::WaitableEvents as well as other blocking in
leveldb code itself.

BUG=697612
==========

to

==========
Use correct task traits for mojo leveldb env background tasks.

These background tasks can do file operations, which might involve
blocking using base::WaitableEvents as well as other blocking in
leveldb code itself.

BUG=697612

Review-Url: https://codereview.chromium.org/2838663002
Cr-Commit-Position: refs/heads/master@{#466786}
Committed:
https://chromium.googlesource.com/chromium/src/+/9a16c13f62099154b115bf2e3464...
==========

[commit-bot: I haz the power, 2017-04-24 22:04:24]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/9a16c13f62099154b115bf2e3464...