[tools/android] Replace FlagReplacer with flag_changer equivalent

tools/resource_prefetch_predictor/prefetch_benchmark.py

Index: tools/resource_prefetch_predictor/prefetch_benchmark.py
diff --git a/tools/resource_prefetch_predictor/prefetch_benchmark.py b/tools/resource_prefetch_predictor/prefetch_benchmark.py
index e31bd1d1ad212a27f127fe1de5b71aa29b151ebf..fae9d24d80eaf5065c5985e66a59f9b49206339e 100755
--- a/tools/resource_prefetch_predictor/prefetch_benchmark.py
+++ b/tools/resource_prefetch_predictor/prefetch_benchmark.py
@@ -29,6 +29,7 @@ sys.path.append(os.path.join(_SRC_PATH, 'build', 'android'))
 import devil_chromium
 
 sys.path.append(os.path.join(_SRC_PATH, 'third_party', 'catapult', 'devil'))
+from devil.android import flag_changer
 from devil.android.sdk import intent
 
 import prefetch_predictor_common
@@ -68,7 +69,7 @@ def _Setup(device, database_filename):
 
   # Make sure that the speculative prefetch predictor is enabled to ensure
   # that the disk database is re-created.
-  with device_setup.FlagReplacer(
+  with flag_changer.CustomCommandLineFlags(
       device, chrome_package.cmdline_file, ['--disable-fre']):
     # Launch Chrome for the first time to recreate the local state.
     launch_intent = intent.Intent(