BrowserOptions.extra_browser_args is now a set.

tools/perf/metrics/v8_object_stats.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.
 
 import json
 import logging
 
 from metrics import Metric
 
 _COUNTER_NAMES = [
@@ skipping 142 matching lines @@
   It does this by enabling the --track_gc_object_stats flag on V8 and reading
   these statistics from the StatsTableMetric.
   """
 
   def __init__(self):
     super(V8ObjectStatsMetric, self).__init__()
     self._results = None
 
   @classmethod
   def CustomizeBrowserOptions(cls, options):
-    options.AppendExtraBrowserArg('--enable-stats-table')
-    options.AppendExtraBrowserArg('--enable-benchmarking')
-    options.AppendExtraBrowserArg(
-        '--js-flags=--track_gc_object_stats --expose_gc')
+    options.AppendExtraBrowserArgs([
+        '--enable-stats-table',
+        '--enable-benchmarking',
+        '--js-flags=--track_gc_object_stats --expose_gc'
+    ])
 
   def Start(self, page, tab):
     """Do Nothing."""
     pass
 
   def Stop(self, page, tab):
     """Get the values in the stats table after the page is loaded."""
     self._results = tab.EvaluateJavaScript("""
  (function(counters) {
    var results = {};
    if (!window.chrome || !window.chrome.benchmarking)
     return results;
    window.gc();  // Trigger GC to ensure stats are checkpointed.
    for (var i = 0; i < counters.length; i++)
      results[counters[i]] = chrome.benchmarking.counterForRenderer(counters[i]);
    return results;
  })(%s);
  """ % json.dumps(_COUNTER_NAMES))
     if not self._results:
       logging.warning('No V8 object stats from website: ' + page.display_url)
 
   def AddResults(self, tab, results):
     """Add results for this page to the results object."""
     assert self._results != None, 'Must call Stop() first'
     for counter_name in self._results:
       results.Add(counter_name, 'kb', self._results[counter_name] / 1024.0)