[Findit] Fix Key error in build_failure handler.

appengine/findit/handlers/build_failure.py

 # Copyright 2014 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.
 
 from collections import defaultdict
 import copy
 from datetime import datetime
 import logging
 import os
 
@@ skipping 235 matching lines @@
           'try_job': try_job_result,
           'heuristic_analysis': {
               'suspected_cls': heuristic_result['suspected_cls']
           },
           'tests': tests if tests != [NON_SWARMING] else [],
           'first_failure': heuristic_result['first_failure'],
           'last_pass': heuristic_result['last_pass'],
           'supported': heuristic_result['supported']
       }
 
-      if try_job_result['status'] == result_status.FLAKY:
+      if ('status' not in try_job_result or
+          try_job_result['status'] in NO_TRY_JOB_REASON_MAP.values()):
+        # There is no try job info but only heuristic result.
+        try_job_result['status'] = try_job_result.get(
+            'status', result_status.UNKNOWN)
+        step_updated_results['unclassified_failures'].append(final_result)
+      elif try_job_result['status'] == result_status.FLAKY:
         step_updated_results['flaky_failures'].append(final_result)
-      elif try_job_result['status'] in NO_TRY_JOB_REASON_MAP.values():
-        # There is no try job info but only heuristic result.
-        step_updated_results['unclassified_failures'].append(final_result)
       else:
         step_updated_results['reliable_failures'].append(final_result)
 
   return updated_results
 
 
 class BuildFailure(BaseHandler):
   PERMISSION_LEVEL = Permission.ANYONE
 
   def _ShowDebugInfo(self):
@@ skipping 125 matching lines @@
         'data': self._PrepareDataForCompileFailure(analysis),
       }
     else:
       return {
         'template': 'build_failure.html',
         'data': self._PrepareDataForTestFailures(analysis, build_info),
       }
 
   def HandlePost(self):  # pragma: no cover
     return self.HandleGet()