Fix the repaint disabling decorator to be consistent with Telemetry disabling style

tools/perf/measurements/repaint_unittest.py

 # Copyright 2014 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 unittest
-
 from telemetry import decorators
 from telemetry.page import page as page_module
 from telemetry.testing import options_for_unittests
 from telemetry.testing import page_test_test_case
 from telemetry.util import wpr_modes
 
 from measurements import smoothness
 from page_sets import repaint_helpers
 
 
@@ skipping 13 matching lines @@
      Runs repaint measurement on a simple page and verifies
      that all metrics were added to the results. The test is purely functional,
      i.e. it only checks if the metrics are present and non-zero.
   """
 
   def setUp(self):
     self._options = options_for_unittests.GetCopy()
     self._options.browser_options.wpr_mode = wpr_modes.WPR_OFF
 
   # Previously this test was disabled on chromeos, see crbug.com/483212.
-  @unittest.skip("flaky") # crbug.com/715962
+  @decorators.Disabled("all") # crbug.com/715962
   def testRepaint(self):
     ps = self.CreateEmptyPageSet()
     ps.AddStory(TestRepaintPage(ps, ps.base_dir))
     measurement = smoothness.Repaint()
     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 14 matching lines @@
 
     # Make sure that we don't have extra timeline based metrics that are not
     # related to smoothness.
     mainthread_jank = results.FindAllPageSpecificValuesNamed(
         'responsive-total_big_jank_thread_time')
     self.assertEquals(len(mainthread_jank), 0)
 
   @decorators.Disabled('android')
   def testCleanUpTrace(self):
     self.TestTracingCleanedUp(smoothness.Repaint, self._options)