[Findit] Check the explicit culprit from try-job if it is set.

appengine/findit/waterfall/identify_try_job_culprit_pipeline.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.
 
 from common.git_repository import GitRepository
 from common.http_client_appengine import HttpClientAppengine as HttpClient
 from common.pipeline_wrapper import BasePipeline
 from model import analysis_status
 from model.wf_try_job import WfTryJob
 from model.wf_try_job_data import WfTryJobData
@@ skipping 59 matching lines @@
       The failed revision from compile_results, or None if not found.
     """
     if not compile_result:
       return None
 
     report = compile_result.get('report')
 
     if not report:
       return None
 
+    if report.get('culprit'):
+      return report.get('culprit')
+
     return IdentifyTryJobCulpritPipeline._GetFailedRevisionFromResultsDict(
         report.get('result', {}))
 
   def _FindCulpritForEachTestFailure(self, blame_list, result):
     # For test failures, the try job will run against every revision,
     # so we need to traverse the result dict in chronological order to identify
     # the culprits for each failed step or test.
     culprit_map = {}
     failed_revisions = []
     for revision in blame_list:
@@ skipping 92 matching lines @@
       if (result_to_update and
           result_to_update[-1]['try_job_id'] == try_job_id):
         result_to_update[-1].update(result)
       else:  # pragma: no cover
         result_to_update.append(result)
 
     try_job_result.status = analysis_status.COMPLETED
     try_job_result.put()
 
     return result.get('culprit') if result else None