Mark json results failures as unexpected in python tests.

Mark json results failures as unexpected in python tests.

If we don't mark the failures as unexpected, the result-reading
logic on the bots views the failures as expected and hence
ignores them, leading us to let bad changes through :(.

TBR=ojan@chromium.org, viettrungluu@chromium.org, tonyg@chromium.org, grt@chromium.org
BUG=264859, 323212, 398027
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=286761

[Dirk Pranke, 2014-07-31 00:31:16]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-07-31 00:33:47]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/430933004/20001

[commit-bot: I haz the power, 2014-07-31 00:33:48]

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

[commit-bot: I haz the power, 2014-07-31 00:33:49]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[Dirk Pranke, 2014-07-31 00:38:47]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-07-31 00:39:45]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/430933004/20001

[ojan, 2014-07-31 00:53:45]

lgtm

[grt (UTC plus 2), 2014-07-31 01:03:12]

lgtm

[viettrungluu, 2014-07-31 01:34:14]

lgtm

[commit-bot: I haz the power, 2014-07-31 12:28:26]

Change committed as 286761