Disable failing telemetry unit tests on chromeos.

tools/perf/measurements/smoothness_unittest.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 import sys
 
 from telemetry.core import wpr_modes
 from telemetry import decorators
 from telemetry.page import page
 from telemetry.unittest_util import options_for_unittests
 from telemetry.unittest_util import page_test_test_case
@@ skipping 64 matching lines @@
       sys.stderr.write("Expected category filter: %s\n" %
                        repr(expected_category_filter))
       sys.stderr.write("Actual category filter filter: %s\n" %
                        repr(actual_category_filter))
     self.assertEquals(expected_category_filter, actual_category_filter)
 
   def setUp(self):
     self._options = options_for_unittests.GetCopy()
     self._options.browser_options.wpr_mode = wpr_modes.WPR_OFF
 
+  @decorators.Disabled('chromeos')  # crbug.com/483212
   def testSmoothness(self):
     ps = self.CreatePageSetFromFileInUnittestDataDir('scrollable_page.html')
     measurement = smoothness.Smoothness()
     results = self.RunMeasurement(measurement, ps, options=self._options)
     self.assertEquals(0, len(results.failures))
 
     frame_times = results.FindAllPageSpecificValuesNamed('frame_times')
     self.assertEquals(len(frame_times), 1)
     self.assertGreater(frame_times[0].GetRepresentativeNumber(), 0)
 
@@ skipping 36 matching lines @@
     max_frame_delay = results.FindAllPageSpecificValuesNamed('max_frame_delay')
     self.assertEquals(1, len(max_frame_delay))
     self.assertGreater(max_frame_delay[0].GetRepresentativeNumber, 0)
 
     frame_lengths = results.FindAllPageSpecificValuesNamed('frame_lengths')
     self.assertEquals(1, len(frame_lengths))
     self.assertGreater(frame_lengths[0].GetRepresentativeNumber, 0)
 
   def testCleanUpTrace(self):
     self.TestTracingCleanedUp(smoothness.Smoothness, self._options)