R22 [autotest] Apply re-login hack to power_LoadTest

BUG=chromium-os:139166
TEST=power_LoadTest

Change-Id: Id83dd87169261ee3892238a8a41315b7c488840b
Reviewed-on: https://gerrit.chromium.org/gerrit/32645
Tested-by: Kris Rambish <krisr@chromium.org>
Reviewed-by: Nirnimesh <nirnimesh@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>
diff --git a/client/site_tests/power_LoadTest/power_LoadTest.py b/client/site_tests/power_LoadTest/power_LoadTest.py
index 80e4951..4fca373 100755
--- a/client/site_tests/power_LoadTest/power_LoadTest.py
+++ b/client/site_tests/power_LoadTest/power_LoadTest.py
@@ -164,8 +164,6 @@
             latch = self._testServer.add_wait_url('/status')
 
             # the act of logging in will launch chrome with external extension.
-            # NOTE: self.login() will log out the current session if it's
-            # currently logged in.
             self.login()
 
             # stop powerd
@@ -188,6 +186,11 @@
                 logging.info('Exiting due to low battery')
                 break
 
+            self.logout()
+            # Work around until crosbug.com/139166 is fixed
+            self.pyauto.ExecuteJavascriptInOOBEWebUI('Oobe.showSigninUI();'
+                'window.domAutomationController.send("ok");')
+
         t1 = time.time()
         self._tmp_keyvals['minutes_battery_life'] = (t1 - t0) / 60