autotest: Schedule attenuated performance tests nightly

We now have 3 dedicated groamer cells (combination grover/roaming)
ready to run nightly performance tests.

BUG=chromium:333443
TEST=None

Change-Id: I2acdfb6d24cfe3c287e8bf195eb82ebc88ddcaaf
Reviewed-on: https://chromium-review.googlesource.com/185482
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>
diff --git a/suite_scheduler.ini b/suite_scheduler.ini
index fbf336b..b1f9a7b 100644
--- a/suite_scheduler.ini
+++ b/suite_scheduler.ini
@@ -260,6 +260,12 @@
 branch_specs: >=R34
 pool: wificell
 
+[WiFi_Attenuated_Performance]
+run_on: nightly
+suite: wifi_atten_perf
+branch_specs: >=R34
+pool: wificell
+
 [WiMAX]
 run_on: nightly
 suite: wimax