Attempt #4 to convert telemetry to the typ framework.

tools/telemetry/telemetry/web_perf/timeline_based_measurement_unittest.py

Index: tools/telemetry/telemetry/web_perf/timeline_based_measurement_unittest.py
diff --git a/tools/telemetry/telemetry/web_perf/timeline_based_measurement_unittest.py b/tools/telemetry/telemetry/web_perf/timeline_based_measurement_unittest.py
index 5518c1ebb99fd8befc5433bda3cdf0a92ae9a632..7e3d26152454e598c7ac57f495d398d22887ca85 100644
--- a/tools/telemetry/telemetry/web_perf/timeline_based_measurement_unittest.py
+++ b/tools/telemetry/telemetry/web_perf/timeline_based_measurement_unittest.py
@@ -13,6 +13,7 @@ from telemetry.page import page_set
 from telemetry.results import page_test_results
 from telemetry.timeline import model as model_module
 from telemetry.timeline import async_slice
+from telemetry.unittest_util import browser_test_case
 from telemetry.unittest_util import options_for_unittests
 from telemetry.unittest_util import page_test_test_case
 from telemetry.value import scalar
@@ -201,9 +202,12 @@ class TestTimelinebasedMeasurementPage(page_module.Page):
 class TimelineBasedMeasurementTest(page_test_test_case.PageTestTestCase):
 
   def setUp(self):
+    browser_test_case.teardown_browser()
     self._options = options_for_unittests.GetCopy()
     self._options.browser_options.wpr_mode = wpr_modes.WPR_OFF
 
+  # This test is flaky when run in parallel on the mac: crbug.com/426676
+  @benchmark.Disabled('mac')
   def testSmoothnessTimelineBasedMeasurementForSmoke(self):
     ps = self.CreateEmptyPageSet()
     ps.AddPage(TestTimelinebasedMeasurementPage(
@@ -221,6 +225,8 @@ class TimelineBasedMeasurementTest(page_test_test_case.PageTestTestCase):
         'DrawerAnimation-frame_time_discrepancy')
     self.assertEquals(len(v), 1)
 
+  # This test is flaky when run in parallel on the mac: crbug.com/426676
+  @benchmark.Disabled('mac')
   def testFastTimelineBasedMeasurementForSmoke(self):
     ps = self.CreateEmptyPageSet()
     ps.AddPage(TestTimelinebasedMeasurementPage(
@@ -256,7 +262,8 @@ class TimelineBasedMeasurementTest(page_test_test_case.PageTestTestCase):
     self.assertGreaterEqual(v[0].value, 200.0)
 
   # Disabled since mainthread_jank metric is not supported on windows platform.
-  @benchmark.Disabled('win')
+  # Also, flaky on the mac when run in parallel: crbug.com/426676
+  @benchmark.Disabled('win', 'mac')
   def testMainthreadJankTimelineBasedMeasurement(self):
     ps = self.CreateEmptyPageSet()
     ps.AddPage(TestTimelinebasedMeasurementPage(