mac: Expose keychain access frequency to Telemetry.

tools/perf/measurements/task_execution_time.py

Index: tools/perf/measurements/task_execution_time.py
diff --git a/tools/perf/measurements/task_execution_time.py b/tools/perf/measurements/task_execution_time.py
index 48029ed5adde50cda58856642ee64ae5d291484e..5a96385a1bdbbbcc7c03483db0bb83d149a01bae 100644
--- a/tools/perf/measurements/task_execution_time.py
+++ b/tools/perf/measurements/task_execution_time.py
@@ -2,10 +2,10 @@
 # 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 telemetry.core.platform import tracing_category_filter
 from telemetry.core.platform import tracing_options
 from telemetry.timeline.model import TimelineModel
-from telemetry.page import page_test
 from telemetry.util import statistics
 from telemetry.value import scalar
 
@@ -17,7 +17,7 @@ _CATEGORIES = ['webkit.console',
               'cc',
               'v8']
 
-class TaskExecutionTime(page_test.PageTest):
+class TaskExecutionTime(PageTestMeasurement):
 
   _TIME_OUT_IN_SECONDS = 60
   _NUMBER_OF_RESULTS_TO_DISPLAY = 10
@@ -44,6 +44,8 @@ class TaskExecutionTime(page_test.PageTest):
     self._renderer_thread = timeline_model.GetRendererThreadFromTabId(tab.id)
 
   def ValidateAndMeasurePage(self, page, tab, results):
+    super(TaskExecutionTime, self).ValidateAndMeasurePage(page, tab, results)
+
     tasks = TaskExecutionTime.GetTasks(self._renderer_thread.parent)
 
     sorted_tasks = sorted(tasks,