mac: Expose keychain access frequency to Telemetry.

tools/perf/measurements/thread_times.py

Index: tools/perf/measurements/thread_times.py
diff --git a/tools/perf/measurements/thread_times.py b/tools/perf/measurements/thread_times.py
index 918a06f9bf33cf6f47e9fc3a5328160863f9589a..5bd777cb29cd2e04f5a86424cf9a24363ec65b70 100644
--- a/tools/perf/measurements/thread_times.py
+++ b/tools/perf/measurements/thread_times.py
@@ -1,12 +1,13 @@
 # Copyright 2014 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 measurements import PageTestMeasurement
 from measurements import timeline_controller
 from metrics import timeline
 from telemetry.core.platform import tracing_category_filter
-from telemetry.page import page_test
 
-class ThreadTimes(page_test.PageTest):
+class ThreadTimes(PageTestMeasurement):
   def __init__(self):
     super(ThreadTimes, self).__init__('RunSmoothness')
     self._timeline_controller = None
@@ -33,6 +34,8 @@ class ThreadTimes(page_test.PageTest):
     self._timeline_controller.Stop(tab)
 
   def ValidateAndMeasurePage(self, page, tab, results):
+    super(ThreadTimes, self).ValidateAndMeasurePage(page, tab, results)
+
     metric = timeline.ThreadTimesTimelineMetric()
     renderer_thread = \
         self._timeline_controller.model.GetRendererThreadFromTabId(tab.id)