BrowserOptions.extra_browser_args is now a set.

tools/perf/metrics/smoothness.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 os
 
 from telemetry.core import util
 
 TIMELINE_MARKER = 'smoothness_scroll'
 
 class SmoothnessMetrics(object):
   def __init__(self, tab):
     self._tab = tab
     with open(
       os.path.join(os.path.dirname(__file__),
                    'smoothness.js')) as f:
       js = f.read()
       tab.ExecuteJavaScript(js)
 
   @classmethod
   def CustomizeBrowserOptions(cls, options):
-    options.AppendExtraBrowserArg('--enable-gpu-benchmarking')
+    options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')
 
   def Start(self):
     self._tab.ExecuteJavaScript(
         'window.__renderingStats = new __RenderingStats();'
         'window.__renderingStats.start()')
 
   def SetNeedsDisplayOnAllLayersAndStart(self):
     self._tab.ExecuteJavaScript(
         'chrome.gpuBenchmarking.setNeedsDisplayOnAllLayers();'
         'window.__renderingStats = new __RenderingStats();'
@@ skipping 143 matching lines @@
               Average(s.touch_ui_latency, s.touch_ui_count, 1000, 3),
               data_type='unimportant')
   results.Add('average_touch_acked_latency', 'ms',
               Average(s.touch_acked_latency, s.touch_acked_count,
                       1000, 3),
               data_type='unimportant')
   results.Add('average_scroll_update_latency', 'ms',
               Average(s.scroll_update_latency, s.scroll_update_count,
                       1000, 3),
               data_type='unimportant')