Collect tab timing information for use in telementry-based startup tests

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 44 matching lines @@
                        for h in MEMORY_HISTOGRAMS]
 
   def WillNavigateToPage(self, page, tab):
     page.script_to_evaluate_on_commit = self.page_cycler_js
 
   def DidNavigateToPage(self, page, tab):
     for h in self.histograms:
       h.Start(page, tab)
 
   def CustomizeBrowserOptions(self, options):
-    options.AppendExtraBrowserArg('--dom-automation')
+    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')
+
     # Temporarily disable typical_25 page set on mac.
     if sys.platform == 'darwin' and sys.argv[-1].endswith('/typical_25.json'):
       print 'typical_25 is currently disabled on mac. Skipping test.'
       sys.exit(0)
 
   def MeasureMemory(self, tab, results):
     memory = tab.browser.memory_stats
     if not memory['Browser']:
       return
 
@@ skipping 68 matching lines @@
     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)