Add stress tests to server/tests whitelist.

Review URL: http://codereview.chromium.org/1528039
diff --git a/utils/site_whitelist_tests b/utils/site_whitelist_tests
index 9b365c6..f9a6f6a 100644
--- a/utils/site_whitelist_tests
+++ b/utils/site_whitelist_tests
@@ -8,6 +8,9 @@
 /usr/local/autotest/client/tests/unixbench/control
 /usr/local/autotest/client/tests/sleeptest/control
 /usr/local/autotest/server/tests/iperf/control.srv
+/usr/local/autotest/server/tests/iperf/control.stress.srv
 /usr/local/autotest/server/tests/netperf2/control.srv
+/usr/local/autotest/server/tests/netperf2/control.stress.srv
 /usr/local/autotest/server/tests/netpipe/control.srv
+/usr/local/autotest/server/tests/netpipe/control.stress.srv
 /usr/local/autotest/server/tests/sleeptest/control