Fix reftest crash logs

Fix reftest crash logs

This patch fixes a long-standing bug where crashing reftests would not
show some crash logs on the layout tests results page.

single_test_runner.py has an optimization to not run reftests when
the base test crashes. This optimization accidentally failed to write
crash logs (done through write_test_result(...)) as well. This patch
fixes this bug and adds a small test.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201147

[pdr., 2015-08-23 03:17:02]

pdr@chromium.org changed reviewers:
+ dpranke@chromium.org, joelo@chromium.org, ojan@chromium.org

[Dirk Pranke, 2015-08-25 19:36:10]

lgtm, thanks! (and sorry for the delay, was ooo ...)

[pdr., 2015-08-25 19:43:50]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2015-08-25 19:44:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1312693002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1312693002/1

[commit-bot: I haz the power, 2015-08-25 20:24:48]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=201147

[pdr., 2015-08-26 21:38:37]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1318813005/ by pdr@chromium.org.

The reason for reverting is: May be causing win failures, see
http://crbug.com/524248#50.