[perf] Disable tab_switching.tough_energy_cases on mac-reference

tools/perf/benchmarks/tab_switching.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.
 
 from core import perf_benchmark
 
 from measurements import tab_switching
 import page_sets
 from telemetry import benchmark
 
@@ skipping 50 matching lines @@
   test = tab_switching.TabSwitching
   page_set = page_sets.FiveBlankPagesPageSet
   options = {'pageset_repeat': 10}
 
   @classmethod
   def Name(cls):
     return 'tab_switching.five_blank_pages'
 
 
 @benchmark.Enabled('has tabs')
-# http://crbug.com/460084, http://crbug.com/488067
-@benchmark.Disabled('android', 'linux')
+# http://crbug.com/460084, http://crbug.com/488067, http://crbug.com/634347
+@benchmark.Disabled('android', 'linux', 'mac-reference')
 class TabSwitchingToughEnergyCases(perf_benchmark.PerfBenchmark):
   """This test records the MPArch.RWH_TabSwitchPaintDuration histogram.
 
   The histogram is a measure of the time between when a tab was requested to be
   shown, and when first paint occurred. The script opens each page in a
   different tab, waits for them to load, and then switches to each tab and
   records the metric. The pages were written by hand to stress energy usage.
   """
   test = tab_switching.TabSwitching
   page_set = page_sets.ToughEnergyCasesPageSet
@@ skipping 13 matching lines @@
   shown, and when first paint occurred. The script opens each page in different
   tabs, waits for them to load, and then switches to each tab and records the
   metric. The pages were chosen by hand to stress the image decoding system.
   """
   test = tab_switching.TabSwitching
   page_set = page_sets.ToughImageCasesPageSet
 
   @classmethod
   def Name(cls):
     return 'tab_switching.tough_image_cases'