BrowserOptions.extra_browser_args is now a set.

tools/perf/measurements/skpicture_printer.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.
 import os
 
 from telemetry.page import page_measurement
 
 
 _JS = 'chrome.gpuBenchmarking.printToSkPicture("{0}");'
 
 
 class SkpicturePrinter(page_measurement.PageMeasurement):
   def AddCommandLineOptions(self, parser):
     parser.add_option('-s', '--skp-outdir',
                       help='Output directory for the SKP files')
 
   def CustomizeBrowserOptions(self, options):
-    options.extra_browser_args.extend(['--enable-gpu-benchmarking',
-                                       '--no-sandbox',
-                                       '--enable-deferred-image-decoding',
-                                       '--force-compositing-mode'])
+    options.AppendExtraBrowserArgs(['--enable-gpu-benchmarking',
+                                    '--no-sandbox',
+                                    '--enable-deferred-image-decoding',
+                                    '--force-compositing-mode'])
 
   def MeasurePage(self, page, tab, results):
     skp_outdir = self.options.skp_outdir
     if not skp_outdir:
       raise Exception('Please specify --skp-outdir')
     outpath = os.path.abspath(
         os.path.join(skp_outdir,
                      page.url_as_file_safe_name))
     # Replace win32 path separator char '\' with '\\'.
     js = _JS.format(outpath.replace('\\', '\\\\'))
     tab.EvaluateJavaScript(js)
     results.Add('output_path', 'path', outpath)