[telemetry] Simplify the way PageRunner is called.

tools/perf/perf_tools/page_cycler.py

 # Copyright (c) 2012 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.
 
 """The page cycler measurement.
 
 This measurement registers a window load handler in which is forces a layout and
 then records the value of performance.now(). This call to now() measures the
 time from navigationStart (immediately after the previous page's beforeunload
 event) until after the layout in the page's load event. In addition, two garbage
@@ skipping 10 matching lines @@
 from perf_tools import histogram_metric
 from telemetry.core import util
 from telemetry.page import page_measurement
 
 MEMORY_HISTOGRAMS = [
     {'name': 'V8.MemoryExternalFragmentationTotal', 'units': 'percent'},
     {'name': 'V8.MemoryHeapSampleTotalCommitted', 'units': 'kb'},
     {'name': 'V8.MemoryHeapSampleTotalUsed', 'units': 'kb'}]
 
 class PageCycler(page_measurement.PageMeasurement):
+  def __init__(self, *args, **kwargs):
+    super(PageCycler, self).__init__(*args, **kwargs)
+
+    with open(os.path.join(os.path.dirname(__file__),
+                           'page_cycler.js'), 'r') as f:
+      self._page_cycler_js = f.read()
+
+    self._start_commit_charge = None
+    self._histograms = None
+
   def AddCommandLineOptions(self, parser):
     # The page cyclers should default to 10 iterations. In order to change the
     # default of an option, we must remove and re-add it.
     pageset_repeat_option = parser.get_option('--pageset-repeat')
     pageset_repeat_option.default = 10
     parser.remove_option('--pageset-repeat')
     parser.add_option(pageset_repeat_option)
 
-  def WillRunPageSet(self, tab, results):
-    # Avoid paying for a cross-renderer navigation on the first page on legacy
-    # page cyclers which use the filesystem.
-    if tab.browser.http_server:
-      tab.Navigate(tab.browser.http_server.UrlOf('nonexistent.html'))
+  def SetUpBrowser(self, browser):
+    self._start_commit_charge = browser.memory_stats['SystemCommitCharge']
 
-    with open(os.path.join(os.path.dirname(__file__),
-                           'page_cycler.js'), 'r') as f:
-      self.page_cycler_js = f.read()  # pylint: disable=W0201
-
-    # pylint: disable=W0201
-    self.start_commit_charge = tab.browser.memory_stats['SystemCommitCharge']
-
-    # pylint: disable=W0201
-    self.histograms = [histogram_metric.HistogramMetric(
+    self._histograms = [histogram_metric.HistogramMetric(
                            h, histogram_metric.RENDERER_HISTOGRAM)
                        for h in MEMORY_HISTOGRAMS]
 
+  def DidStartHTTPServer(self, tab):
+    # Avoid paying for a cross-renderer navigation on the first page on legacy
+    # page cyclers which use the filesystem.
+    tab.Navigate(tab.browser.http_server.UrlOf('nonexistent.html'))
+
   def WillNavigateToPage(self, page, tab):
-    page.script_to_evaluate_on_commit = self.page_cycler_js
+    page.script_to_evaluate_on_commit = self._page_cycler_js
 
   def DidNavigateToPage(self, page, tab):
-    for h in self.histograms:
+    for h in self._histograms:
       h.Start(page, tab)
 
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArg('--enable-stats-collection-bindings')
     options.AppendExtraBrowserArg('--js-flags=--expose_gc')
     options.AppendExtraBrowserArg('--no-sandbox')
 
     # Old commandline flags used for reference builds.
     options.AppendExtraBrowserArg('--dom-automation')
 
@@ skipping 28 matching lines @@
       AddSummary('ProportionalSetSize', 'vm_proportional_set_size_final_')
       AddSummary('VMPeak', 'vm_peak_size_')
       AddSummary('WorkingSetSizePeak', '%s_peak_size_' % metric)
 
     AddSummariesForProcessTypes(['Browser'], 'browser')
     AddSummariesForProcessTypes(['Renderer'], 'renderer')
     AddSummariesForProcessTypes(['Gpu'], 'gpu')
     AddSummariesForProcessTypes(['Browser', 'Renderer', 'Gpu'], 'total')
 
     results.AddSummary('commit_charge', 'kb',
-                       memory['SystemCommitCharge'] - self.start_commit_charge,
+                       memory['SystemCommitCharge'] - self._start_commit_charge,
                        data_type='unimportant')
     results.AddSummary('processes', 'count', memory['ProcessCount'],
                        data_type='unimportant')
 
   def MeasureIO(self, tab, results):
     io_stats = tab.browser.io_stats
     if not io_stats['Browser']:
       return
 
     def AddSummariesForProcessType(process_type_io, process_type_trace):
@@ skipping 19 matching lines @@
                            data_type='unimportant')
     AddSummariesForProcessType('Browser', 'browser')
     AddSummariesForProcessType('Renderer', 'renderer')
     AddSummariesForProcessType('Gpu', 'gpu')
 
   def MeasurePage(self, page, tab, results):
     def _IsDone():
       return bool(tab.EvaluateJavaScript('__pc_load_time'))
     util.WaitFor(_IsDone, 60)
 
-    for h in self.histograms:
+    for h in self._histograms:
       h.GetValue(page, tab, results)
 
     results.Add('page_load_time', 'ms',
                 int(float(tab.EvaluateJavaScript('__pc_load_time'))),
                 chart_name='times')
 
   def DidRunPageSet(self, tab, results):
     self.MeasureMemory(tab, results)
     self.MeasureIO(tab, results)