Fix purging logic for dom_storage caches

Fix purging logic for dom_storage caches

Do not try purging the caches when no unopened database was found.

BUG=610551
Committed: https://crrev.com/bfc745d81e242821f10aa3eaece65ab70f685725
Cr-Commit-Position: refs/heads/master@{#395991}

[ssid, 2016-05-25 03:25:39]

ssid@chromium.org changed reviewers:
+ michaeln@chromium.org

[ssid, 2016-05-25 03:25:39]

Small fix in the purge code. It was trying to purge even when no unopened
database was found, but we only purge unopened. 
ptal thanks.

[michaeln, 2016-05-25 19:18:44]

lgtm

[ssid, 2016-05-25 19:24:27]

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

[commit-bot: I haz the power, 2016-05-25 19:25:08]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2015473002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2015473002/1

[commit-bot: I haz the power, 2016-05-25 21:05:15]

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

[commit-bot: I haz the power, 2016-05-25 21:05:16]

Dry run: This issue passed the CQ dry run.

[commit-bot: I haz the power, 2016-05-25 21:05:32]

Dry run: None

[ssid, 2016-05-25 21:23:18]

The CQ bit was checked by ssid@chromium.org

[commit-bot: I haz the power, 2016-05-25 21:24:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2015473002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2015473002/1

[commit-bot: I haz the power, 2016-05-25 21:30:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-25 21:33:40]

Description was changed from

==========
Fix purging logic for dom_storage caches

Do not try purging the caches when no unopened database was found.

BUG=610551
==========

to

==========
Fix purging logic for dom_storage caches

Do not try purging the caches when no unopened database was found.

BUG=610551

Committed: https://crrev.com/bfc745d81e242821f10aa3eaece65ab70f685725
Cr-Commit-Position: refs/heads/master@{#395991}
==========

[commit-bot: I haz the power, 2016-05-25 21:33:41]

Patchset 1 (id:??) landed as
https://crrev.com/bfc745d81e242821f10aa3eaece65ab70f685725
Cr-Commit-Position: refs/heads/master@{#395991}