[Findit] Record error if swarming task completes with exit_code as 2.

appengine/findit/waterfall/test/process_swarming_task_result_pipeline_test.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 datetime
 
 from model import analysis_status
 from model.wf_swarming_task import WfSwarmingTask
 from waterfall import process_swarming_task_result_pipeline
 from waterfall import swarming_util
@@ skipping 92 matching lines @@
     'reliable_tests': ['TestSuite1.test3']
 }
 
 
 class ProcessSwarmingTaskResultPipelineTest(wf_testcase.WaterfallTestCase):
 
   def _MockedGetSwarmingTaskResultById(self, task_id, _):
     swarming_task_results = {
         'task_id1': {
             'state': 'COMPLETED',
+            'exit_code': '1',
             'tags': [
                 'priority:25',
                 'ref_name:abc_tests'
             ],
             'outputs_ref': {
                 'isolatedserver': _ISOLATED_SERVER,
                 'namespace': 'default-gzip',
                 'isolated': 'shard1_isolated'
             },
             'created_ts': '2016-02-10T18:32:06.538220',
@@ skipping 112 matching lines @@
     self.assertEqual(self.step_name, step_name)
     self.assertEqual('abc_tests', task_info[0])
     self.assertEqual([], task_info[1])
 
     task = WfSwarmingTask.Get(
         self.master_name, self.builder_name, self.build_number, self.step_name)
 
     self.assertEqual(analysis_status.ERROR, task.status)
     self.assertEqual({}, task.tests_statuses)
     self.assertEqual({}, task.classified_tests)