Reland [Android] Set platform mode as default for perf tests.

build/android/test_runner.py

 #!/usr/bin/env python
 #
 # 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.
 
 """Runs all types of tests from one unified interface."""
 
 import argparse
 import collections
@@ skipping 775 matching lines @@
           'Did not find device %s among attached device. Attached devices: %s'
           % (test_device, ', '.join(attached_devices)))
     return test_device
 
   else:
     if not attached_devices:
       raise device_errors.NoDevicesError()
     return sorted(attached_devices)
 
 
-# TODO(rnephew): Add perf when ready to switch to platform mode as default.
-_DEFAULT_PLATFORM_MODE_TESTS = ['gtest', 'instrumentation']
+_DEFAULT_PLATFORM_MODE_TESTS = ['gtest', 'instrumentation', 'perf']
 
 
 def RunTestsCommand(args): # pylint: disable=too-many-return-statements
   """Checks test type and dispatches to the appropriate function.
 
   Args:
     args: argparse.Namespace object.
 
   Returns:
     Integer indicated exit code.
@@ skipping 195 matching lines @@
     if e.is_infra_error:
       return constants.INFRA_EXIT_CODE
     return constants.ERROR_EXIT_CODE
   except: # pylint: disable=W0702
     logging.exception('Unrecognized error occurred.')
     return constants.ERROR_EXIT_CODE
 
 
 if __name__ == '__main__':
   sys.exit(main())