[Offline Pages] Fix crash in chrome://offline-internals

[Offline Pages] Fix crash in chrome://offline-internals

The base::Value API changed semantics and internally started using
std::move on the Value passed into it.  We assumed that the pointer
would remain valid even after being passed to the base::Value that
would own it.

This patch uses the new std::unique_ptr API and reorders the code so
we don't fall victim to this bug.

BUG=711472

[dewittj, 2017-04-13 22:19:57]

Description was changed from

==========
[Offline Pages] Fix crash in chrome://offline-internals

The base::Value API changed semantics and internally started using
std::move on the Value passed into it.  We assumed that the pointer
would remain valid even after being passed to the base::Value that
would own it.

This patch uses the new std::unique_ptr API and reorders the code so
we don't fall victim to this bug.

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

to

==========
[Offline Pages] Fix crash in chrome://offline-internals

The base::Value API changed semantics and internally started using
std::move on the Value passed into it.  We assumed that the pointer
would remain valid even after being passed to the base::Value that
would own it.

This patch uses the new std::unique_ptr API and reorders the code so
we don't fall victim to this bug.

BUG=711472

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

[dewittj, 2017-04-13 22:19:57]

dewittj@chromium.org changed reviewers:
+ chili@chromium.org, estade@chromium.org

[dewittj, 2017-04-13 22:20:09]

PTAL, thanks

[dewittj, 2017-04-13 22:21:41]

Description was changed from

==========
[Offline Pages] Fix crash in chrome://offline-internals

The base::Value API changed semantics and internally started using
std::move on the Value passed into it.  We assumed that the pointer
would remain valid even after being passed to the base::Value that
would own it.

This patch uses the new std::unique_ptr API and reorders the code so
we don't fall victim to this bug.

BUG=711472

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

to

==========
[Offline Pages] Fix crash in chrome://offline-internals

The base::Value API changed semantics and internally started using
std::move on the Value passed into it.  We assumed that the pointer
would remain valid even after being passed to the base::Value that
would own it.

This patch uses the new std::unique_ptr API and reorders the code so
we don't fall victim to this bug.

BUG=711472
==========

[dewittj, 2017-04-13 22:22:07]

dewittj@chromium.org changed reviewers:
+ dbeam@chromium.org
- estade@chromium.org

[dewittj, 2017-04-13 22:22:25]

Whoops, git-cl owners picked an "Emeritus."  dbeam, PTAL.

[chili, 2017-04-13 22:43:12]

lgtm

Thanks for fixing this!

[dewittj, 2017-04-14 22:55:09]

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

[commit-bot: I haz the power, 2017-04-14 22:55:36]

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, 2017-04-14 23:27:02]

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

[commit-bot: I haz the power, 2017-04-14 23:27:03]

Dry run: This issue passed the CQ dry run.

[Dan Beam, 2017-04-18 02:09:02]

lgtm

[dewittj, 2017-04-18 02:11:10]

The CQ bit was checked by dewittj@chromium.org

[commit-bot: I haz the power, 2017-04-18 02:11:33]

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 02:17:21]

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

[commit-bot: I haz the power, 2017-04-18 02:17:22]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[dewittj, 2017-04-18 16:50:41]

well, it looks like I was outraced by vabr@ who happened to make the exact same
change as me.  Closing.