Fix document mode migration again

Fix document mode migration again

The document mode migration code was changed in
4804efe6387351c7802a2e9f34afe84e7ccbe7fe
to skip document mode migration if a shared preference was not set.
On older versions of Chrome, that shared preference wasn't set
even though the user was in document mode. Migration was skipped and
all tabs were lost.

Revert to the old logic of using another shared preference to help
determine if the user is in document mode.

BUG=646146
Committed: https://crrev.com/0a7922abb655a17a03ee108190b017b9a72ab899
Cr-Commit-Position: refs/heads/master@{#418722}

[Theresa, 2016-09-14 21:27:46]

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

[commit-bot: I haz the power, 2016-09-14 21:28:41]

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

[Theresa, 2016-09-14 21:30:01]

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

[Theresa, 2016-09-14 21:30:07]

twellington@chromium.org changed reviewers:
+ dfalcantara@chromium.org

[Theresa, 2016-09-14 21:30:08]

ptal

[commit-bot: I haz the power, 2016-09-14 21:31:02]

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

[gone, 2016-09-14 21:34:44]

/me sighs.

lgtm

[Theresa, 2016-09-14 21:36:49]

The CQ bit was unchecked by twellington@chromium.org

[Theresa, 2016-09-14 21:36:49]

The CQ bit was checked by twellington@chromium.org

[Theresa, 2016-09-14 21:36:59]

The CQ bit was unchecked by twellington@chromium.org

[commit-bot: I haz the power, 2016-09-14 21:37:03]

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

[Theresa, 2016-09-14 21:38:11]

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

[Theresa, 2016-09-14 21:38:23]

The CQ bit was unchecked by twellington@chromium.org

[Theresa, 2016-09-14 21:38:23]

The CQ bit was checked by twellington@chromium.org

[Theresa, 2016-09-14 21:38:23]

The patchset sent to the CQ was uploaded after l-g-t-m from
dfalcantara@chromium.org
Link to the patchset: https://codereview.chromium.org/2340743004/#ps40001
(title: "Add comment")

[commit-bot: I haz the power, 2016-09-14 21:39:18]

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

[Theresa, 2016-09-14 21:44:58]

The CQ bit was unchecked by twellington@chromium.org

[Theresa, 2016-09-14 22:25:31]

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

[commit-bot: I haz the power, 2016-09-14 22:26:14]

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

[Theresa, 2016-09-14 22:33:20]

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

[commit-bot: I haz the power, 2016-09-14 22:34:13]

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

[gone, 2016-09-14 22:41:46]

lgtm, but you probably want to use a try finally

[Theresa, 2016-09-14 22:50:21]

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

[commit-bot: I haz the power, 2016-09-14 22:50:58]

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

[Theresa, 2016-09-14 22:54:26]

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

[commit-bot: I haz the power, 2016-09-14 22:55:02]

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, 2016-09-15 00:13:35]

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

[commit-bot: I haz the power, 2016-09-15 00:13:36]

Dry run: This issue passed the CQ dry run.

[Theresa, 2016-09-15 00:14:27]

The CQ bit was checked by twellington@chromium.org

[Theresa, 2016-09-15 00:14:27]

The patchset sent to the CQ was uploaded after l-g-t-m from
dfalcantara@chromium.org
Link to the patchset: https://codereview.chromium.org/2340743004/#ps140001
(title: "Use TabbedModePersistencePolicy.getStateFileName()")

[commit-bot: I haz the power, 2016-09-15 00:14:59]

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, 2016-09-15 00:20:55]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2016-09-15 00:22:44]

Description was changed from

==========
Fix document mode migration again

The document mode migration code was changed in
4804efe6387351c7802a2e9f34afe84e7ccbe7fe
to skip document mode migration if a shared preference was not set.
On older versions of Chrome, that shared preference wasn't set
even though the user was in document mode. Migration was skipped and
all tabs were lost.

Revert to the old logic of using another shared preference to help
determine if the user is in document mode.

BUG=646146
==========

to

==========
Fix document mode migration again

The document mode migration code was changed in
4804efe6387351c7802a2e9f34afe84e7ccbe7fe
to skip document mode migration if a shared preference was not set.
On older versions of Chrome, that shared preference wasn't set
even though the user was in document mode. Migration was skipped and
all tabs were lost.

Revert to the old logic of using another shared preference to help
determine if the user is in document mode.

BUG=646146

Committed: https://crrev.com/0a7922abb655a17a03ee108190b017b9a72ab899
Cr-Commit-Position: refs/heads/master@{#418722}
==========

[commit-bot: I haz the power, 2016-09-15 00:22:45]

Patchset 8 (id:??) landed as
https://crrev.com/0a7922abb655a17a03ee108190b017b9a72ab899
Cr-Commit-Position: refs/heads/master@{#418722}