Disable TabTest.testHighlight in telemetry_unittests

tools/telemetry/telemetry/core/tab_unittest.py

Index: tools/telemetry/telemetry/core/tab_unittest.py
diff --git a/tools/telemetry/telemetry/core/tab_unittest.py b/tools/telemetry/telemetry/core/tab_unittest.py
index 4540810420ec5c70434432728e2bd7a975af3a08..c7d50c6fb3cb378bd94944cbf5a3dc4215a63125 100644
--- a/tools/telemetry/telemetry/core/tab_unittest.py
+++ b/tools/telemetry/telemetry/core/tab_unittest.py
@@ -97,8 +97,9 @@ class TabTest(tab_test_case.TabTestCase):
       self._tab.browser._platform_backend = original_platform_backend
 
   # Test failing on android: http://crbug.com/437057
-  # Also, for chromeos: http://crbug.com/412713
-  @decorators.Disabled('android', 'chromeos')
+  # Also for chromeos: http://crbug.com/412713
+  # and mac: http://crbug.com/468675
+  @decorators.Disabled('android', 'chromeos', 'mac')
   def testHighlight(self):
     self.assertEquals(self._tab.url, 'about:blank')
     options = tracing_options.TracingOptions()