[Android] Always enable multiprocessing mode in the forwarder.

build/android/pylib/perf/setup.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.
 
 """Generates test runner factory and tests for performance tests."""
 
 import json
 import fnmatch
 import logging
 import os
@@ skipping 54 matching lines @@
     A tuple of (TestRunnerFactory, tests, devices).
   """
   # TODO(bulach): remove this once the bot side lands. BUG=318369
   constants.SetBuildType('Release')
   if os.path.exists(constants.PERF_OUTPUT_DIR):
     shutil.rmtree(constants.PERF_OUTPUT_DIR)
   os.makedirs(constants.PERF_OUTPUT_DIR)
 
   # Before running the tests, kill any leftover server.
   test_environment.CleanupLeftoverProcesses()
-  forwarder.Forwarder.UseMultiprocessing()
 
   # We want to keep device affinity, so return all devices ever seen.
   all_devices = _GetAllDevices()
 
   steps_dict = _GetStepsDict(test_options)
   sorted_step_names = sorted(steps_dict['steps'].keys())
 
   if test_options.test_filter:
     sorted_step_names = fnmatch.filter(sorted_step_names,
                                        test_options.test_filter)
 
   flaky_steps = []
   if test_options.flaky_steps:
     with file(test_options.flaky_steps, 'r') as f:
       flaky_steps = json.load(f)
 
   def TestRunnerFactory(device, shard_index):
     return test_runner.TestRunner(
         test_options, device, shard_index, len(all_devices),
         steps_dict, flaky_steps)
 
   return (TestRunnerFactory, sorted_step_names, all_devices)