Set appropriate working directory on build failure

Set appropriate working directory on build failure.

Bisect working directory was not reset on build failures, because of this svn commands were executed in wrong directory.

BUG=391109
NOTRY=true

Committed: https://crrev.com/f0b61609929172b2b1cf619342105ab4ee53542d
Cr-Commit-Position: refs/heads/master@{#293942}

[prasadv, 2014-09-08 22:59:50]

prasadv@chromium.org changed reviewers:
+ qyearsley@chromium.org

[qyearsley, 2014-09-09 00:59:47]

On 2014/09/08 23:00:14, prasadv wrote:

LGTM

[qyearsley, 2014-09-09 00:59:57]

https://codereview.chromium.org/555503004/diff/40001/tools/bisect-perf-regres...
File tools/bisect-perf-regression.py (right):

https://codereview.chromium.org/555503004/diff/40001/tools/bisect-perf-regres...
tools/bisect-perf-regression.py:1530: cwd = os.getcwd()
(Note, somewhat unrelated to this CL: this variable name could probably be
improved. cwd stands for "current working directory", and once you chdir away
from it, it's no longer the current working directory... same goes for
"src_cwd". Should probably just be called "src_dir".)

[prasadv, 2014-09-09 15:35:15]

The CQ bit was checked by prasadv@chromium.org

[commit-bot: I haz the power, 2014-09-09 15:35:57]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/prasadv@chromium.org/555503004/40001

[commit-bot: I haz the power, 2014-09-09 15:39:06]

Committed patchset #3 (id:40001) as 22779638be476b1b0b49020f1e7cf23f63f0b983

[commit-bot: I haz the power, 2014-09-10 03:53:28]

Patchset 3 (id:??) landed as
https://crrev.com/f0b61609929172b2b1cf619342105ab4ee53542d
Cr-Commit-Position: refs/heads/master@{#293942}