mac: Expose keychain access frequency to Telemetry.

tools/perf/measurements/tab_switching.py

Index: tools/perf/measurements/tab_switching.py
diff --git a/tools/perf/measurements/tab_switching.py b/tools/perf/measurements/tab_switching.py
index 41290dc07de244e293b794f3c951467bfae2d0d0..23ef78df21b3839a3fa7a1b5de88de2c0fa5f0b8 100644
--- a/tools/perf/measurements/tab_switching.py
+++ b/tools/perf/measurements/tab_switching.py
@@ -12,15 +12,15 @@ Power usage is also measured.
 
 import time
 
+from measurements import PageTestMeasurement
 from metrics import power
 from telemetry.core import util
-from telemetry.page import page_test
 from telemetry.value import histogram
 from telemetry.value import histogram_util
 
 # TODO: Revisit this test once multitab support is finalized.
 
-class TabSwitching(page_test.PageTest):
+class TabSwitching(PageTestMeasurement):
 
   # Amount of time to measure, in seconds.
   SAMPLE_TIME = 30
@@ -31,6 +31,7 @@ class TabSwitching(page_test.PageTest):
     self._power_metric = None
 
   def CustomizeBrowserOptions(self, options):
+    super(TabSwitching, self).CustomizeBrowserOptions(options)
     options.AppendExtraBrowserArgs([
         '--enable-stats-collection-bindings'
     ])
@@ -99,3 +100,5 @@ class TabSwitching(page_test.PageTest):
         histogram.HistogramValue(None, display_name, 'ms',
                                  raw_value_json=diff_histogram,
                                  important=False))
+
+    super(TabSwitching, self).ValidateAndMeasurePage(page, tab, results)