mac: Expose keychain access frequency to Telemetry.

tools/perf/measurements/polymer_load.py

Index: tools/perf/measurements/polymer_load.py
diff --git a/tools/perf/measurements/polymer_load.py b/tools/perf/measurements/polymer_load.py
index a373a4fcccf962f586d55d55774e3fe5a7464fa1..85046a5c4c321d1b01a04a8c28a16022612b33b9 100644
--- a/tools/perf/measurements/polymer_load.py
+++ b/tools/perf/measurements/polymer_load.py
@@ -2,8 +2,8 @@
 # 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.page import page
-from telemetry.page import page_test
 from telemetry.value import scalar
 
 
@@ -28,8 +28,10 @@ class PageForPolymerLoad(page.Page):
     action_runner.WaitForJavaScriptCondition('window.__polymer_ready')
 
 
-class PolymerLoadMeasurement(page_test.PageTest):
+class PolymerLoadMeasurement(PageTestMeasurement):
   def ValidateAndMeasurePage(self, _, tab, results):
+    super(PolymerLoadMeasurement, self).ValidateAndMeasurePage(
+        page, tab, results)
     result = int(tab.EvaluateJavaScript('__polymer_ready_time'))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'Total', 'ms', result))