Clear away any lingering error before testing SkError.

Clear away any lingering error before testing SkError.

Looks like something's setting an error before ErrorTest runs on our new
Venue8 bots.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/fbe4136845fd68f583f9f9bfb628706c4b87480b

[mtklein, 2014-09-11 19:38:13]

The CQ bit was checked by mtklein@google.com

[mtklein, 2014-09-11 19:38:21]

mtklein@google.com changed reviewers:
+ humper@google.com

[commit-bot: I haz the power, 2014-09-11 19:39:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/551973004/1

[commit-bot: I haz the power, 2014-09-11 19:39:01]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from a valid reviewer till 2014-09-12 01:39 UTC

[commit-bot: I haz the power, 2014-09-11 21:40:42]

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

[commit-bot: I haz the power, 2014-09-11 21:40:43]

Try jobs failed on following builders:
  Test-Android-Venue8-PowerVR-x86-Debug-Trybot on tryserver.skia
(http://108.170.220.21:10117/builders/Test-Android-Venue8-PowerVR-x86-Debug-Tr...)

[mtklein, 2014-09-11 21:41:30]

I'm going to declare those test failures successes... they got past DM 2 for 2
(nanobench failures are some other problem).

[mtklein, 2014-09-11 21:41:45]

The CQ bit was checked by mtklein@google.com

[mtklein, 2014-09-11 21:41:46]

lgtm

[commit-bot: I haz the power, 2014-09-11 21:41:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/551973004/1

[commit-bot: I haz the power, 2014-09-11 21:42:05]

Committed patchset #1 (id:1) as fbe4136845fd68f583f9f9bfb628706c4b87480b