Disable flaky SystemHealthBenchmarkSmokeTest test

system_health.memory_desktop/browse:news:flipboard:2018

Bug: 978358
Change-Id: Id9328fb1d053f6284b5ed5c05cbf41764d877017
Tbr: perezju@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1675687
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Juan Antonio Navarro Pérez <perezju@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Auto-Submit: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672026}

tools/perf/benchmarks/system_health_smoke_test.py

@@ -138,6 +138,9 @@ _DISABLED_TESTS = frozenset({
   # crbug.com/937006
   'system_health.memory_mobile/browse:news:toi',
 
+  # crbug.com/978358
+  'system_health.memory_desktop/browse:news:flipboard:2018',
+
   # The following tests are disabled because they are disabled on the perf
   # waterfall (using tools/perf/expectations.config) on one platform or another.
   # They may run fine on the CQ, but it isn't worth the bot time to run them.