Fail remote trybot builds when HWTests time out.

If hwtest times out on a remote trybot, the build should not be marked
as successful, since the build didn't really succeed -- the user asked
to test their change using remote trybots and this didn't really happen.

BUG=chromium:236025
TEST=Unittests.
STATUS=Fixed

Change-Id: I11d990ff02d540b0dda9afedd270ae986dcb23e5
Reviewed-on: https://gerrit.chromium.org/gerrit/49373
Tested-by: David James <davidjames@chromium.org>
Reviewed-by: Ryan Cui <rcui@chromium.org>
Commit-Queue: David James <davidjames@chromium.org>
diff --git a/buildbot/cbuildbot_config.py b/buildbot/cbuildbot_config.py
index 555e9db..03586ca 100755
--- a/buildbot/cbuildbot_config.py
+++ b/buildbot/cbuildbot_config.py
@@ -76,11 +76,12 @@
       if not my_config['hw_tests']:
         my_config['hw_tests'] = HWTestConfig.DefaultList(
             num=constants.HWTEST_TRYBOT_NUM, pool=constants.HWTEST_TRYBOT_POOL,
-            file_bugs=False)
+            critical=True, file_bugs=False)
       else:
         for hw_config in my_config['hw_tests']:
           hw_config.num = constants.HWTEST_TRYBOT_NUM
           hw_config.pool = constants.HWTEST_TRYBOT_POOL
+          hw_config.critical = True
           hw_config.file_bugs = False
 
     # Default to starting with a fresh chroot on remote trybot runs.