autotest: Use explicit timeout keyword in JavaScript calls.

BUG=chromium:682812
TEST=trybots

Change-Id: I1ae37ef0625d29d299878698b9cda8468eb430bd
Reviewed-on: https://chromium-review.googlesource.com/431959
Commit-Ready: Achuith Bhandarkar <achuith@chromium.org>
Tested-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Jacob Dufault <jdufault@chromium.org>
diff --git a/client/common_lib/cros/enrollment.py b/client/common_lib/cros/enrollment.py
index 883706d..5f38cf1 100644
--- a/client/common_lib/cros/enrollment.py
+++ b/client/common_lib/cros/enrollment.py
@@ -11,7 +11,8 @@
 def _ExecuteOobeCmd(browser, cmd):
     logging.info('Invoking ' + cmd)
     oobe = browser.oobe
-    oobe.WaitForJavaScriptExpression('typeof Oobe !== \'undefined\'', 10)
+    oobe.WaitForJavaScriptExpression('typeof Oobe !== \'undefined\'',
+                                     timeout=10)
     oobe.ExecuteJavaScript(cmd)