telemetry: support old builds that still use disable-gesture-requirement-for-media-playback flag.

tools/perf/benchmarks/blink_perf.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 core import path_util
 from core import perf_benchmark
 
 from telemetry import benchmark
@@ skipping 127 matching lines @@
       self._blink_perf_js = f.read()
 
   def WillNavigateToPage(self, page, tab):
     del tab  # unused
     page.script_to_evaluate_on_commit = self._blink_perf_js
 
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs([
         '--js-flags=--expose_gc',
         '--enable-experimental-web-platform-features',
+        # Note that both this flag:
         '--ignore-autoplay-restrictions',
+        # and this flag:
+        '--disable-gesture-requirement-for-media-playback',
+        # should be used until every build from
+        # ToT to Stable switches over to one flag or another. This is to support
+        # reference builds.
+        # --disable-gesture-requirement-for-media-playback is the old one and
+        # can be removed after M60 goes to stable.
         '--enable-experimental-canvas-features',
         # TODO(qinmin): After fixing crbug.com/592017, remove this command line.
         '--reduce-security-for-testing'
     ])
     if 'content-shell' in options.browser_type:
       options.AppendExtraBrowserArgs('--expose-internals-for-testing')
 
   def _ContinueTestRunWithTracing(self, tab):
     tracing_categories = tab.EvaluateJavaScript(
         'testRunner.tracingCategories')
@@ skipping 228 matching lines @@
 
 @benchmark.Owner(emails=['hayato@chromium.org'])
 class BlinkPerfShadowDOM(_BlinkPerfBenchmark):
   tag = 'shadow_dom'
   subdir = 'ShadowDOM'
 
   @classmethod
   def ShouldDisable(cls, possible_browser):  # http://crbug.com/702319
     return possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X'