[test runner] Handle missing files gracefully.

[test runner] Handle missing files gracefully.

This returns a proper test result (failure) when files are
missing for setting up the command.

Committed: https://crrev.com/061eca59f8d42d403b3cdde21b680624aa3267dc
Cr-Commit-Position: refs/heads/master@{#33946}

[Michael Achenbach, 2016-02-12 13:22:02]

Description was changed from

==========
[test runner] Handle missing files gracefully.

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

to

==========
[test runner] Handle missing files gracefully.

This returns a proper test result (failure) when files are
missing for setting up the command.
==========

[Michael Achenbach, 2016-02-12 13:22:02]

machenbach@chromium.org changed reviewers:
+ jkummerow@chromium.org, tandrii@chromium.org

[Michael Achenbach, 2016-02-12 13:24:42]

PTAL. This attempts to help debug randomly missing files better:

https://chromium-swarm.appspot.com/user/task/2c9681285e622710

I'm afraid, however, that if the files are indeed missing, the driver will hang
later in the progress indicator, which also relies on opening the files once
more to reconstruct the command. But least we'll see this output before that.

[Michael Achenbach, 2016-02-12 13:24:56]

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

[commit-bot: I haz the power, 2016-02-12 13:24:58]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1696713002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1696713002/1

[Jakob Kummerow, 2016-02-12 13:28:03]

lgtm

[tandrii(chromium), 2016-02-12 13:30:48]

lgtm

[Michael Achenbach, 2016-02-12 13:32:10]

The CQ bit was unchecked by machenbach@chromium.org

[Michael Achenbach, 2016-02-12 13:32:14]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2016-02-12 13:32:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1696713002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1696713002/1

[commit-bot: I haz the power, 2016-02-12 13:54:07]

Description was changed from

==========
[test runner] Handle missing files gracefully.

This returns a proper test result (failure) when files are
missing for setting up the command.
==========

to

==========
[test runner] Handle missing files gracefully.

This returns a proper test result (failure) when files are
missing for setting up the command.
==========

[commit-bot: I haz the power, 2016-02-12 13:54:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-12 13:54:44]

Description was changed from

==========
[test runner] Handle missing files gracefully.

This returns a proper test result (failure) when files are
missing for setting up the command.
==========

to

==========
[test runner] Handle missing files gracefully.

This returns a proper test result (failure) when files are
missing for setting up the command.

Committed: https://crrev.com/061eca59f8d42d403b3cdde21b680624aa3267dc
Cr-Commit-Position: refs/heads/master@{#33946}
==========

[commit-bot: I haz the power, 2016-02-12 13:54:45]

Patchset 1 (id:??) landed as
https://crrev.com/061eca59f8d42d403b3cdde21b680624aa3267dc
Cr-Commit-Position: refs/heads/master@{#33946}