mac: Expose keychain access frequency to Telemetry.

tools/perf/measurements/memory_multi_tab.py

 # Copyright 2013 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.
 
 """Multi tab memory test.
 
 This test is a multi tab test, but we're interested in measurements for
 the entire test rather than each single page.
 """
 
+from measurements import PageTestMeasurement
+from metrics import memory
 
-from metrics import memory
-from telemetry.page import page_test
-
-class MemoryMultiTab(page_test.PageTest):
+class MemoryMultiTab(PageTestMeasurement):
   def __init__(self, *args, **kwargs):
     super(MemoryMultiTab, self).__init__(*args, **kwargs)
     self._memory_metric = None
     # _first_tab is used to make memory measurements
     self._first_tab = None
 
   def DidStartBrowser(self, browser):
     self._memory_metric = memory.MemoryMetric(browser)
 
   def CustomizeBrowserOptions(self, options):
+    super(MemoryMultiTab, self).CustomizeBrowserOptions(options)
     memory.MemoryMetric.CustomizeBrowserOptions(options)
     # Since this is a memory benchmark, we want to sample memory histograms at
     # a high frequency.
     options.AppendExtraBrowserArgs('--memory-metrics')
 
   def TabForPage(self, page, browser):
     return browser.tabs.New()
 
   def DidNavigateToPage(self, page, tab):
     # Start measurement on the first tab.
     if not self._first_tab:
       self._memory_metric.Start(page, tab)
       self._first_tab = tab
 
   def ValidateAndMeasurePage(self, page, tab, results):
+    super(MemoryMultiTab, self).ValidateAndMeasurePage(page, tab, results)
+
     # Finalize measurement on the last tab.
     if len(tab.browser.tabs) == len(page.page_set.pages):
       self._memory_metric.Stop(page, self._first_tab)
       self._memory_metric.AddResults(self._first_tab, results)