[tools/android] Replace FlagReplacer with flag_changer equivalent

tools/android/loading/wpr_helper.py

 #!/usr/bin/python
 #
 # Copyright 2017 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.
 
 """Helper script to launch Chrome on device and WebPageReplay on host."""
 
 import logging
 import optparse
 import os
 import sys
 import time
 
 _SRC_PATH = os.path.abspath(os.path.join(
     os.path.dirname(__file__), os.pardir, os.pardir, os.pardir))
 
 sys.path.append(os.path.join(_SRC_PATH, 'third_party', 'catapult', 'devil'))
 from devil.android import device_utils
+from devil.android import flag_changer
 from devil.android.constants import chrome
 from devil.android.perf import cache_control
 from devil.android.sdk import intent
 
 sys.path.append(os.path.join(_SRC_PATH, 'build', 'android'))
 import devil_chromium
 
 import chrome_setup
 import device_setup
 
 
 def RunChrome(device, cold, chrome_args, package_info):
   """Runs Chrome on the device.
 
   Args:
     device: (DeviceUtils) device to run the tests on.
     cold: (bool) Whether caches should be dropped.
     chrome_args: ([str]) List of arguments to pass to Chrome.
     package_info: (PackageInfo) Chrome package info.
   """
   if not device.HasRoot():
     device.EnableRoot()
 
   cmdline_file = package_info.cmdline_file
   package = package_info.package
-  with device_setup.FlagReplacer(device, cmdline_file, chrome_args):
+  with flag_changer.CustomCommandLineFlags(device, cmdline_file, chrome_args):
     device.ForceStop(package)
 
     if cold:
       chrome_setup.ResetChromeLocalState(device, package)
       cache_control.CacheControl(device).DropRamCaches()
 
     start_intent = intent.Intent(package=package, data='about:blank',
                                  activity=package_info.activity)
     try:
       device.StartActivity(start_intent, blocking=True)
@@ skipping 60 matching lines @@
   with device_setup.RemoteWprHost(device, args[0], options.record,
                                   options.network_condition,
                                   out_log_path=options.wpr_log) as wpr_attr:
     RunChrome(device, options.cold,
               chrome_setup.CHROME_ARGS + wpr_attr.chrome_args,
               chrome.PACKAGE_INFO[options.chrome_package_name])
 
 
 if __name__ == '__main__':
   main()