[Telemetry] Disable spaceport and tough_canvas_cases on mac.

tools/perf/benchmarks/spaceport.py

Index: tools/perf/benchmarks/spaceport.py
diff --git a/tools/perf/benchmarks/spaceport.py b/tools/perf/benchmarks/spaceport.py
index 34baaac5a825440aa42ff49d92fb2eb33db542a9..2d6e43ae55ccbb34ec24c42454bc3f0a5a7cca0f 100644
--- a/tools/perf/benchmarks/spaceport.py
+++ b/tools/perf/benchmarks/spaceport.py
@@ -6,6 +6,7 @@
 
 import logging
 import os
+import sys
 
 from telemetry import test
 from telemetry.core import util
@@ -56,6 +57,8 @@ 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')