sheriff: disable UNSCHEDULED_blink_perf.webgpu_fast_call test

Test is failing on Mac10.14 Tests.

Tbr: johnchen@chromium.org
Bug: 1164115
Change-Id: Iadec9aa292b612e0b01c598b322b149ca1c6d3da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2615721
Commit-Queue: Jiewei Qian  <qjw@chromium.org>
Reviewed-by: Jiewei Qian  <qjw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841329}

tools/perf/benchmarks/benchmark_smoke_unittest.py

@@ -105,7 +105,8 @@ _BLACK_LIST_TEST_NAMES = [
     'tab_switching.typical_25',
     'UNSCHEDULED_oortonline_tbmv2',
     'webrtc',  # crbug.com/932036
-    'v8.runtime_stats.top_25'  # Fails in Windows, crbug.com/1043048
+    'v8.runtime_stats.top_25',  # Fails in Windows, crbug.com/1043048
+    'UNSCHEDULED_blink_perf.webgpu_fast_call',  # crbug.com/1164115
 ]