[Telemetry] Disable spaceport and tough_canvas_cases on mac.

tools/perf/benchmarks/spaceport.py

 # Copyright (c) 2012 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.
 
 """Runs spaceport.io's PerfMarks benchmark."""
 
 import logging
 import os
+import sys
 
 from telemetry import test
 from telemetry.core import util
 from telemetry.page import page_measurement
 from telemetry.page import page_set
 
 
 class _SpaceportMeasurement(page_measurement.PageMeasurement):
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs('--disable-gpu-vsync')
@@ skipping 30 matching lines @@
       results.Add(trace, 'objects (bigger is better)', float(result_dict[key]),
                   chart_name=chart, data_type='unimportant')
     results.Add('Score', 'objects (bigger is better)',
                 [float(x) for x in result_dict.values()])
 
 
 class Spaceport(test.Test):
   """spaceport.io's PerfMarks benchmark."""
   test = _SpaceportMeasurement
 
+  enabled = sys.platform != 'darwin'
+
   def CreatePageSet(self, options):
     spaceport_dir = os.path.join(util.GetChromiumSrcDir(), 'chrome', 'test',
         'data', 'third_party', 'spaceport')
     return page_set.PageSet.FromDict(
         {'pages': [{'url': 'file://index.html'}]},
         spaceport_dir)