Fix PathProvider to not modify result when DIR_TEST_DATA does not exist

Fix PathProvider to not modify result when DIR_TEST_DATA does not exist

Calling code expects result to be unmodified when PathProvider fails.

BUG=568225
Committed: https://crrev.com/6e147810ef5bc645258ba100f5793bf05fb9716c
Cr-Commit-Position: refs/heads/master@{#364740}

[maniscalco, 2015-12-09 20:58:04]

maniscalco@chromium.org changed reviewers:
+ brettw@chromium.org

[maniscalco, 2015-12-09 20:58:04]

Brett, would you please review this change?

Also, I'd be interested in your thoughts on how to test this.  In order to test
it, I'd like to have DIR_SOURCE_ROOT/base/test/data not exist.  But I suspect
that will break other test :)  Maybe set the CR_SOURCE_ROOT environment
variable, call PathProvider, then restore it?

[brettw, 2015-12-10 18:37:23]

I have no idea how to test this. It's probably fine, I'm actually more worried
about other cases than this one regressing, but hopefully people will notice the
DCHECK and fix any problems that pop up.

LGTM

[maniscalco, 2015-12-10 18:45:11]

On 2015/12/10 18:37:23, brettw wrote:
> I have no idea how to test this. It's probably fine, I'm actually more worried
> about other cases than this one regressing, but hopefully people will notice
the
> DCHECK and fix any problems that pop up.
> 
> LGTM

FWIW, I tried writing a test that sets CR_SOURCE_ROOT to a bogus path, but
didn't get far because PathProviderPosix requires it to exist.

[maniscalco, 2015-12-10 19:12:48]

The CQ bit was checked by maniscalco@chromium.org

[commit-bot: I haz the power, 2015-12-10 19:14:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1513823002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1513823002/1

[commit-bot: I haz the power, 2015-12-10 21:19:24]

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

[commit-bot: I haz the power, 2015-12-10 21:19:25]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[maniscalco, 2015-12-11 17:14:43]

The CQ bit was checked by maniscalco@chromium.org

[commit-bot: I haz the power, 2015-12-11 17:15:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1513823002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1513823002/1

[commit-bot: I haz the power, 2015-12-11 18:23:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-11 18:24:30]

Description was changed from

==========
Fix PathProvider to not modify result when DIR_TEST_DATA does not exist

Calling code expects result to be unmodified when PathProvider fails.

BUG=568225
==========

to

==========
Fix PathProvider to not modify result when DIR_TEST_DATA does not exist

Calling code expects result to be unmodified when PathProvider fails.

BUG=568225

Committed: https://crrev.com/6e147810ef5bc645258ba100f5793bf05fb9716c
Cr-Commit-Position: refs/heads/master@{#364740}
==========

[commit-bot: I haz the power, 2015-12-11 18:24:30]

Patchset 1 (id:??) landed as
https://crrev.com/6e147810ef5bc645258ba100f5793bf05fb9716c
Cr-Commit-Position: refs/heads/master@{#364740}