Add a ScopedNSAutoreleasePool to TabModelTest.PersistSelectionChange

Add a ScopedNSAutoreleasePool to TabModelTest.PersistSelectionChange.

Refactoring TabModel introduces some autoreleased NSArray* that
increase the lifetime of Tab and thus of the registered observers.
Introduce a ScopedNSAutoreleasePool to ensure they are cleaned
before the ChromeBrowserState is cleaned.

BUG=687207
Review-Url: https://codereview.chromium.org/2678883002
Cr-Commit-Position: refs/heads/master@{#448303}
Committed: https://chromium.googlesource.com/chromium/src/+/6bb97fbb52d03df492bc510ac8e9014d8c16ffae

[sdefresne, 2017-02-06 17:01:17]

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

[sdefresne, 2017-02-06 17:01:25]

sdefresne@chromium.org changed reviewers:
+ rohitrao@chromium.org

[sdefresne, 2017-02-06 17:01:25]

Please take a look.

[commit-bot: I haz the power, 2017-02-06 17:01:35]

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, 2017-02-06 17:11:45]

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

[commit-bot: I haz the power, 2017-02-06 17:11:46]

Dry run: This issue passed the CQ dry run.

[sdefresne, 2017-02-06 17:11:53]

On 2017/02/06 17:01:25, sdefresne wrote:
> Please take a look.

This should fix flakyness of TabModelTest.PersistSelectionChange.

[rohitrao (ping after 24h), 2017-02-06 17:31:46]

lgtm

Also consider changing the first line of the description to something like:

Add a ScopedNSAutoreleasePool to TabModelTest.PersistSelectionChange.

Just so it's easier to figure out where the pool was added, if you're only
skimming through the first lines of CLs.

https://codereview.chromium.org/2678883002/diff/1/ios/chrome/browser/tabs/tab...
File ios/chrome/browser/tabs/tab_model_unittest.mm (right):

https://codereview.chromium.org/2678883002/diff/1/ios/chrome/browser/tabs/tab...
ios/chrome/browser/tabs/tab_model_unittest.mm:834:
base::mac::ScopedNSAutoreleasePool pool;
Can you please add a comment explaining why this pool is necessary?

https://codereview.chromium.org/2678883002/diff/1/ios/chrome/browser/tabs/tab...
ios/chrome/browser/tabs/tab_model_unittest.mm:873:
base::RunLoop().RunUntilIdle();
Why is this necessary?  Does this drain the pool?  Could you just delete the
pool here instead?

[sdefresne, 2017-02-06 17:36:18]

Description was changed from

==========
Add a ScopedNSAutoreleasePool to control object dealloc order.

Refactoring TabModel introduces some autoreleased NSArray* that
increase the lifetime of Tab and thus of the registered observers.
Introduce a ScopedNSAutoreleasePool to ensure they are cleaned
before the ChromeBrowserState is cleaned.

BUG=687207
==========

to

==========
Add a ScopedNSAutoreleasePool to TabModelTest.PersistSelectionChange.

Refactoring TabModel introduces some autoreleased NSArray* that
increase the lifetime of Tab and thus of the registered observers.
Introduce a ScopedNSAutoreleasePool to ensure they are cleaned
before the ChromeBrowserState is cleaned.

BUG=687207
==========

[sdefresne, 2017-02-06 17:46:43]

PTAL

https://codereview.chromium.org/2678883002/diff/1/ios/chrome/browser/tabs/tab...
File ios/chrome/browser/tabs/tab_model_unittest.mm (right):

https://codereview.chromium.org/2678883002/diff/1/ios/chrome/browser/tabs/tab...
ios/chrome/browser/tabs/tab_model_unittest.mm:834:
base::mac::ScopedNSAutoreleasePool pool;
On 2017/02/06 17:31:46, rohitrao wrote:
> Can you please add a comment explaining why this pool is necessary?

Done.

https://codereview.chromium.org/2678883002/diff/1/ios/chrome/browser/tabs/tab...
ios/chrome/browser/tabs/tab_model_unittest.mm:873:
base::RunLoop().RunUntilIdle();
On 2017/02/06 17:31:46, rohitrao wrote:
> Why is this necessary?  Does this drain the pool?  Could you just delete the
> pool here instead?

This is unrelated to draining the pool.

It is there because restoring a session sends a task to the UI thread with a
callback on the UI thread (see https://codereview.chromium.org/2674293002/ where
I make this callback thread-safe). So this fixes another possible source of
flaky-ness.

I've put a comment why this is there.

[rohitrao (ping after 24h), 2017-02-06 17:47:50]

lgtm

[sdefresne, 2017-02-06 17:50:54]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2017-02-06 17:51:10]

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, 2017-02-06 18:06:46]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1486403454291300,
"parent_rev": "f99a7d41c0a70c4723c21031ac582ac942b59811", "commit_rev":
"6bb97fbb52d03df492bc510ac8e9014d8c16ffae"}

[commit-bot: I haz the power, 2017-02-06 18:07:21]

Description was changed from

==========
Add a ScopedNSAutoreleasePool to TabModelTest.PersistSelectionChange.

Refactoring TabModel introduces some autoreleased NSArray* that
increase the lifetime of Tab and thus of the registered observers.
Introduce a ScopedNSAutoreleasePool to ensure they are cleaned
before the ChromeBrowserState is cleaned.

BUG=687207
==========

to

==========
Add a ScopedNSAutoreleasePool to TabModelTest.PersistSelectionChange.

Refactoring TabModel introduces some autoreleased NSArray* that
increase the lifetime of Tab and thus of the registered observers.
Introduce a ScopedNSAutoreleasePool to ensure they are cleaned
before the ChromeBrowserState is cleaned.

BUG=687207

Review-Url: https://codereview.chromium.org/2678883002
Cr-Commit-Position: refs/heads/master@{#448303}
Committed:
https://chromium.googlesource.com/chromium/src/+/6bb97fbb52d03df492bc510ac8e9...
==========

[commit-bot: I haz the power, 2017-02-06 18:07:22]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/6bb97fbb52d03df492bc510ac8e9...