[Findit] Fix bugs when pulling gtest result.

appengine/findit/waterfall/swarming_util.py

 # Copyright 2015 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 base64
 from collections import defaultdict
 import json
 import logging
 import urllib
 import zlib
@@ skipping 30 matching lines @@
 }
 
 
 # Urlfetch error codes.
 URLFETCH_DOWNLOAD_ERROR = 100
 URLFETCH_DEADLINE_EXCEEDED_ERROR = 110
 URLFETCH_CONNECTION_CLOSED_ERROR = 120
 EXCEEDED_MAX_RETRIES_ERROR = 210
 
 
+# Outputs_ref is None.
+NO_TASK_OUTPUTS = 300
+
+
 # Other/miscellaneous error codes.
 UNKNOWN = 1000
 
 
 # Swarming task exit codes.
 ALL_TESTS_PASSED = 0
 SOME_TESTS_FAILED = 1
 TASK_FAILED = 2
 
 # Swarming task exit code descriptions.
@@ skipping 201 matching lines @@
   if not data:
     return False
 
   tag_name = 'stepname'
   build_isolated_data = defaultdict(list)
   for item in data:
     if item['failure'] and not item['internal_failure']:
       # Only retrieves test results from tasks which have failures and
       # the failure should not be internal infrastructure failure.
       swarming_step_name = GetTagValue(item['tags'], tag_name)
-      if swarming_step_name in failed_steps:
+      if swarming_step_name in failed_steps and item.get('outputs_ref'):
         isolated_data = _GenerateIsolatedData(item['outputs_ref'])
         build_isolated_data[swarming_step_name].append(isolated_data)
 
   new_steps = []
   for step_name in build_isolated_data:
     failed_steps[step_name]['list_isolated_data'] = (
         build_isolated_data[step_name])
 
     # Create WfStep object for all the failed steps.
     step = WfStep.Create(master_name, builder_name, build_number, step_name)
@@ skipping 188 matching lines @@
   for isolated_data in list_isolated_data:
     output_json, _ = _DownloadTestResults(isolated_data, http_client)
     if not output_json:
       # TODO(lijeffrey): Report/handle error returned from _DownloadTestResults.
       return None
     shard_results.append(output_json)
 
   if len(list_isolated_data) == 1:
     return shard_results[0]
   return _MergeSwarmingTestShards(shard_results)