Fix crash on login.

Fix crash on login.

When OwnerSettingsService::ReloadKeypair() is called, |private_key_| is
replaced with a new value. Thus a reference must be retained when we use
it in another thread.

BUG=chromium:711207
TEST=test_that samus tmp_LoginStressTest
     # https://chromium-review.googlesource.com/c/458138/

Review-Url: https://codereview.chromium.org/2818383002
Cr-Commit-Position: refs/heads/master@{#465096}
Committed: https://chromium.googlesource.com/chromium/src/+/20138f3d0b1f72eb232363cac921dfc8c21812cf

[Shuhei Takahashi, 2017-04-17 03:43:11]

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

[commit-bot: I haz the power, 2017-04-17 03:43:22]

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

[Shuhei Takahashi, 2017-04-17 04:06:21]

Description was changed from

==========
Fix crash on login.

BUG=chromium:711207
TEST=TBD
==========

to

==========
Fix crash on login.

BUG=chromium:711207
TEST=test_that samus tmp_LoginStressTest
     # https://chromium-review.googlesource.com/c/458138/
==========

[commit-bot: I haz the power, 2017-04-17 04:10:26]

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

[commit-bot: I haz the power, 2017-04-17 04:10:27]

Dry run: This issue passed the CQ dry run.

[Shuhei Takahashi, 2017-04-17 04:19:37]

Description was changed from

==========
Fix crash on login.

BUG=chromium:711207
TEST=test_that samus tmp_LoginStressTest
     # https://chromium-review.googlesource.com/c/458138/
==========

to

==========
Fix crash on login.

When OwnerSettingsService::ReloadKeypair() is called, |private_key_| is
replaced with a new value. Thus a reference must be retained when we use
it in another thread.

BUG=chromium:711207
TEST=test_that samus tmp_LoginStressTest
     # https://chromium-review.googlesource.com/c/458138/
==========

[Shuhei Takahashi, 2017-04-17 04:20:25]

nya@chromium.org changed reviewers:
+ alemate@chromium.org, xiyuan@chromium.org

[Shuhei Takahashi, 2017-04-17 04:20:26]

alemate, xiyuan: PTAL

[xiyuan, 2017-04-17 15:47:26]

lgtm but you need owner's blessing from alemate@.

[Alexander Alekseev, 2017-04-17 16:11:39]

lgtm

[Shuhei Takahashi, 2017-04-18 01:19:41]

The CQ bit was checked by nya@chromium.org

[commit-bot: I haz the power, 2017-04-18 01:20:20]

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, 2017-04-18 01:54:48]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1492478381764410, "parent_rev":
"25102b38891fb9d46c865a38c8ae04e2660bb6a8", "commit_rev":
"20138f3d0b1f72eb232363cac921dfc8c21812cf"}

[commit-bot: I haz the power, 2017-04-18 01:55:20]

Description was changed from

==========
Fix crash on login.

When OwnerSettingsService::ReloadKeypair() is called, |private_key_| is
replaced with a new value. Thus a reference must be retained when we use
it in another thread.

BUG=chromium:711207
TEST=test_that samus tmp_LoginStressTest
     # https://chromium-review.googlesource.com/c/458138/
==========

to

==========
Fix crash on login.

When OwnerSettingsService::ReloadKeypair() is called, |private_key_| is
replaced with a new value. Thus a reference must be retained when we use
it in another thread.

BUG=chromium:711207
TEST=test_that samus tmp_LoginStressTest
     # https://chromium-review.googlesource.com/c/458138/

Review-Url: https://codereview.chromium.org/2818383002
Cr-Commit-Position: refs/heads/master@{#465096}
Committed:
https://chromium.googlesource.com/chromium/src/+/20138f3d0b1f72eb232363cac921...
==========

[commit-bot: I haz the power, 2017-04-18 01:55:28]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/20138f3d0b1f72eb232363cac921...