Make ProtoDatabase properly handle failed Init

Make ProtoDatabase properly handle failed Init

When Init fails, further Save/Load calls should just fail (and not
crash). This makes the underlying LevelDB properly handle the Init failed case
and adds tests for that.

Adds LevelDB::InitWithOptions to make it easy to have the Init fail in tests.

Committed: https://crrev.com/1aad174b259bc655e7b9e973fadfc79bc5c00e51
Cr-Commit-Position: refs/heads/master@{#304944}

[cjhopman, 2014-11-19 00:11:36]

cjhopman@chromium.org changed reviewers:
+ mathp@chromium.org

[cjhopman, 2014-11-19 00:11:37]

mathp: *

[Mathieu, 2014-11-19 16:11:01]

Thanks for the fix, lgtm.

[cjhopman, 2014-11-19 22:22:26]

The CQ bit was checked by cjhopman@chromium.org

[commit-bot: I haz the power, 2014-11-19 22:24:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/735823004/20001

[commit-bot: I haz the power, 2014-11-19 23:22:29]

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

[commit-bot: I haz the power, 2014-11-19 23:22:30]

Try jobs failed on following builders:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[cjhopman, 2014-11-19 23:31:29]

The CQ bit was checked by cjhopman@chromium.org

[commit-bot: I haz the power, 2014-11-19 23:34:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/735823004/20001

[cjhopman, 2014-11-19 23:46:32]

The CQ bit was checked by cjhopman@chromium.org

[commit-bot: I haz the power, 2014-11-19 23:46:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/735823004/40001

[commit-bot: I haz the power, 2014-11-20 00:30:16]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2014-11-20 00:31:09]

Patchset 3 (id:??) landed as
https://crrev.com/1aad174b259bc655e7b9e973fadfc79bc5c00e51
Cr-Commit-Position: refs/heads/master@{#304944}