[tools/android] Replace FlagReplacer with flag_changer equivalent

tools/android/loading/device_setup.py

 # Copyright 2016 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 collections
 import contextlib
 import logging
 import os
 import shutil
 import subprocess
 import sys
 import tempfile
 import time
 
 _SRC_DIR = os.path.abspath(os.path.join(
     os.path.dirname(__file__), '..', '..', '..'))
 
 _CATAPULT_DIR = os.path.join(_SRC_DIR, 'third_party', 'catapult')
 sys.path.append(os.path.join(_CATAPULT_DIR, 'devil'))
 from devil.android import device_utils
-from devil.android import flag_changer
 from devil.android import forwarder
 from devil.android.sdk import adb_wrapper
 from devil.android.sdk import intent
 
 sys.path.append(os.path.join(_SRC_DIR, 'build', 'android'))
 from pylib import constants
 from video_recorder import video_recorder
 
 sys.path.append(os.path.join(_SRC_DIR, 'tools', 'perf'))
 from chrome_telemetry_build import chromium_config
@@ skipping 82 matching lines @@
     for command in command_queue:
       command_file.write(subprocess.list2cmdline(command) + ' ;\n')
     command_file.write('exit 0;\n'.format(
         REMOTE_COMMAND_FILE_PATH))
     command_file.flush()
     device.adb.Push(command_file.name, REMOTE_COMMAND_FILE_PATH)
     device.adb.Shell('sh {p} && rm {p}'.format(p=REMOTE_COMMAND_FILE_PATH))
 
 
 @contextlib.contextmanager
-def FlagReplacer(device, command_line_path, new_flags):
-  """Replaces chrome flags in a context, restores them afterwards.
-
-  Args:
-    device: Device to target, from DeviceUtils. Can be None, in which case this
-      context manager is a no-op.
-    command_line_path: Full path to the command-line file.
-    new_flags: Flags to replace.
-  """
-  # If we're logging requests from a local desktop chrome instance there is no
-  # device.
-  if not device:
-    yield
-    return
-  changer = flag_changer.FlagChanger(device, command_line_path)
-  changer.ReplaceFlags(new_flags)
-  try:
-    yield
-  finally:
-    changer.Restore()
-
-
-@contextlib.contextmanager
 def ForwardPort(device, local, remote):
   """Forwards a local port to a remote one on a device in a context."""
   # If we're logging requests from a local desktop chrome instance there is no
   # device.
   if not device:
     yield
     return
   device.adb.Forward(local, remote)
   try:
     yield
@@ skipping 268 matching lines @@
     # speed index measurement.
     connection.ExecuteJavaScript("""
       (function() {
         requestAnimationFrame(function() {
           var screen = window.__speedindex_screen;
           screen.style.background = 'rgb(255, 255, 255)';
         });
       })();
     """)
     yield