[Android] Add ability to generate test trace json for perf tests runs.

build/android/pylib/perf/perf_test_instance.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 json
 import logging
 import os
 import pickle
 import re
 
@@ skipping 61 matching lines @@
     self._max_battery_temp = args.max_battery_temp
     self._min_battery_level = args.min_battery_level
     self._no_timeout = args.no_timeout
     self._output_chartjson_data = args.output_chartjson_data
     self._output_json_list = args.output_json_list
     self._print_step = args.print_step
     self._single_step = (
         ' '.join(args.single_step_command) if args.single_step else None)
     self._steps = args.steps
     self._test_filter = args.test_filter
+    self._trace_output = args.trace_output
     self._write_buildbot_json = args.write_buildbot_json
 
   #override
   def SetUp(self):
     pass
 
   #override
   def TearDown(self):
     pass
 
@@ skipping 137 matching lines @@
     return self._single_step
 
   @property
   def steps(self):
     return self._steps
 
   @property
   def test_filter(self):
     return self._test_filter
 
+  @property
+  def trace_output(self):
+    return self._trace_output
+
 
 class PersistentDataError(base_error.BaseError):
   def __init__(self, message):
     super(PersistentDataError, self).__init__(message)
     self._is_infra_error = True