autotest: fix race condition between cron crash_sender and test invoked

client/site_tests/logging_UserCrash/logging_UserCrash.py

 # Copyright (c) 2010 The Chromium OS 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 grp, logging, os, pwd, re, stat, subprocess
 from signal import SIGSEGV
 from autotest_lib.client.bin import site_crash_test, site_utils, test
 from autotest_lib.client.common_lib import error, utils
 
 _CORE_PATTERN = '/proc/sys/kernel/core_pattern'
@@ skipping 212 matching lines @@
         # Now stackwalk the minidump
         stack = utils.system_output('/usr/bin/minidump_stackwalk %s %s' %
                                     (minidump_path, self._symbol_dir))
         self._verify_stack(stack, basename, from_crash_reporter)
 
 
     def _check_generated_minidump_sending(self, meta_path, minidump_path,
                                           username, crasher_basename,
                                           will_syslog_give_name):
         # Now check that the sending works
-        self._set_sending(True)
         result = self._call_sender_one_crash(
             username=username,
             report=os.path.basename(minidump_path))
         if (not result['send_attempt'] or not result['send_success'] or
             result['report_exists']):
             raise error.TestFail('Minidump not sent properly')
         if will_syslog_give_name:
             if result['exec_name'] != crasher_basename:
                 raise error.TestFail('Executable name incorrect')
         if result['report_kind'] != 'minidump':
@@ skipping 232 matching lines @@
                               'reporter_shutdown',
                               'no_crash',
                               'chronos_crasher',
                               'chronos_crasher_no_consent',
                               'root_crasher',
                               'root_crasher_no_consent',
                               'max_enqueued_crashes',
                               'core_file_persists_in_debug',
                               'core_file_removed_in_production'],
                               initialize_crash_reporter = True)