tast: Run private tests by default.

CQ-DEPEND=CL:1496189
BUG=chromium:875141
TEST=tast_unittest.py

Change-Id: Ie44cfcc6d32d4615ce83fde294ded45fb48962f5
Reviewed-on: https://chromium-review.googlesource.com/1496190
Commit-Ready: Shuhei Takahashi <nya@chromium.org>
Tested-by: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
diff --git a/server/site_tests/tast/tast.py b/server/site_tests/tast/tast.py
index 28bf6c5..aea45af 100644
--- a/server/site_tests/tast/tast.py
+++ b/server/site_tests/tast/tast.py
@@ -95,7 +95,7 @@
     _TEST_DID_NOT_FINISH_MSG = 'Test did not finish'
 
     def initialize(self, host, test_exprs, ignore_test_failures=False,
-                   max_run_sec=3600, install_root='/', run_private_tests=False):
+                   max_run_sec=3600, install_root='/', run_private_tests=True):
         """
         @param host: remote.RemoteHost instance representing DUT.
         @param test_exprs: Array of strings describing tests to run.