Run crash test only on release builds because it's slow on debug

Run crashing test only on release builds because it's slow on debug

fast/dom/shadow/focus-controller-recursion-crash.html was marked SLOW,
but it would be suffice to run it on release builds
to catch any regression.
Disable the test on debug builds.

Original CL: https://codereview.chromium.org/1204213002/
SLOW marked at: https://codereview.chromium.org/1208213002/

BUG=445194
TEST=check if the test is run on release, skipped on debug

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197889

[kochi, 2015-06-26 02:13:08]

kochi@chromium.org changed reviewers:
+ hayato@chromium.org

[kochi, 2015-06-26 03:44:34]

PTAL

[hayato, 2015-06-26 04:03:51]

LGTM.

Could you make the subject of this CL more specific?

[kochi, 2015-06-26 04:13:00]

On 2015/06/26 04:03:51, hayato wrote:
> LGTM.
> 
> Could you make the subject of this CL more specific?

Updated the subject and the description.
Thanks.

[kochi, 2015-06-26 04:13:08]

The CQ bit was checked by kochi@chromium.org

[commit-bot: I haz the power, 2015-06-26 04:13:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1208333003/1

[commit-bot: I haz the power, 2015-06-26 05:13:06]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197889