Add FileNetLogObserver::FileWriter::FlushThenStop(), update FileNetLogObserver::StopObserving() to …

Add FileNetLogObserver::FileWriter::FlushThenStop(), update FileNetLogObserver::StopObserving() to use it.

This cleans up some code where two related functions, whose order of execution must be enforced, are being separately posted to a thread (thus not explicitly enforcing the order of execution). This adds a helper function which internally calls the two functions in the correct order. Now, the helper function is posted instead of the two functions separately. 

BUG=

Review-Url: https://codereview.chromium.org/2658753002
Cr-Commit-Position: refs/heads/master@{#446891}
Committed: https://chromium.googlesource.com/chromium/src/+/3c6b5e31567422169bd1cff7321a70db2a835df6

[wangyix1, 2017-01-26 02:23:29]

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

[commit-bot: I haz the power, 2017-01-26 02:24:25]

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, 2017-01-26 05:25:17]

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

[commit-bot: I haz the power, 2017-01-26 05:25:18]

Dry run: This issue passed the CQ dry run.

[wangyix1, 2017-01-26 22:26:00]

Description was changed from

==========
Add FileNetLogObserver::FileWriter::FlushThenStop(), update
FileNetLogObserver::StopObserving() to use it.


FileNetLogObserver::StopObserving() currently posts two tasks separately to the
file thread:
FileWriter::Flush(), followed by FileWriter::Stop().

Now, it just posts FileWriter::FlushThenStop(), which internally calls Flush(),
then Stop().

BUG=
==========

to

==========
Add FileNetLogObserver::FileWriter::FlushThenStop(), update
FileNetLogObserver::StopObserving() to use it.

This cleans up some code where two related functions, whose order of execution
must be enforced, are being separately posted to a thread (thus not explicitly
enforcing the order of execution). This adds a helper function which internally
calls the two functions in the correct order. Now, the helper function is posted
instead of the two functions separately. 

BUG=
==========

[wangyix1, 2017-01-26 22:26:00]

wangyix@chromium.org changed reviewers:
+ eroman@chromium.org

[wangyix1, 2017-01-26 22:27:41]

PTAL

[eroman, 2017-01-26 23:09:14]

lgtm

[wangyix1, 2017-01-28 01:50:34]

The CQ bit was checked by wangyix@chromium.org

[wangyix1, 2017-01-28 01:50:34]

The patchset sent to the CQ was uploaded after l-g-t-m from eroman@chromium.org
Link to the patchset: https://codereview.chromium.org/2658753002/#ps20001
(title: "Rebase")

[commit-bot: I haz the power, 2017-01-28 01:51:03]

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, 2017-01-28 02:55:03]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1485568234029590,
"parent_rev": "8cdd37a13cbdd5d3906cb675ee02124d866a330d", "commit_rev":
"3c6b5e31567422169bd1cff7321a70db2a835df6"}

[commit-bot: I haz the power, 2017-01-28 02:55:35]

Description was changed from

==========
Add FileNetLogObserver::FileWriter::FlushThenStop(), update
FileNetLogObserver::StopObserving() to use it.

This cleans up some code where two related functions, whose order of execution
must be enforced, are being separately posted to a thread (thus not explicitly
enforcing the order of execution). This adds a helper function which internally
calls the two functions in the correct order. Now, the helper function is posted
instead of the two functions separately. 

BUG=
==========

to

==========
Add FileNetLogObserver::FileWriter::FlushThenStop(), update
FileNetLogObserver::StopObserving() to use it.

This cleans up some code where two related functions, whose order of execution
must be enforced, are being separately posted to a thread (thus not explicitly
enforcing the order of execution). This adds a helper function which internally
calls the two functions in the correct order. Now, the helper function is posted
instead of the two functions separately. 

BUG=

Review-Url: https://codereview.chromium.org/2658753002
Cr-Commit-Position: refs/heads/master@{#446891}
Committed:
https://chromium.googlesource.com/chromium/src/+/3c6b5e31567422169bd1cff7321a...
==========

[commit-bot: I haz the power, 2017-01-28 02:55:36]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/3c6b5e31567422169bd1cff7321a...