Disable testRunPerformanceTestsGtest_end2end on chromeos.

BUG=chromium:754913
TEST=This try run:
https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8921104233557763808

Change-Id: I3aeccc92d91575191e5ab8a3cea8008273afb946
Reviewed-on: https://chromium-review.googlesource.com/c/1477600
Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633623}

tools/perf/scripts_smoke_unittest.py

@@ -150,7 +150,9 @@ class ScriptsSmokeTest(unittest.TestCase):
       shutil.rmtree(tempdir)
 
 
-  @decorators.Disabled('win')  # ".exe" is auto-added which breaks Windows.
+  # Windows: ".exe" is auto-added which breaks Windows.
+  # ChromeOS: crbug.com/754913.
+  @decorators.Disabled('win', 'chromeos')
   def testRunPerformanceTestsGtest_end2end(self):
     tempdir = tempfile.mkdtemp()
     benchmark = 'dummy_gtest'