Disabled service_worker.service_worker_micro_benchmark

It's flaky on Mac and Linux.
BUG=442752
TBR=horo@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/876593004

Cr-Commit-Position: refs/heads/master@{#314253}

tools/perf/benchmarks/service_worker.py

@@ -185,7 +185,7 @@ class ServiceWorkerPerfTest(benchmark.Benchmark):
 
 
 # Disabled due to redness on the tree. crbug.com/442752
-@benchmark.Disabled('reference', 'xp')
+@benchmark.Disabled
 class ServiceWorkerMicroBenchmarkPerfTest(benchmark.Benchmark):
   """This test measures the performance of pages using ServiceWorker.