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

appengine/findit/waterfall/test/identify_try_job_culprit_pipeline_test.py

Index: appengine/findit/waterfall/test/identify_try_job_culprit_pipeline_test.py
diff --git a/appengine/findit/waterfall/test/identify_try_job_culprit_pipeline_test.py b/appengine/findit/waterfall/test/identify_try_job_culprit_pipeline_test.py
index e2de1b0408430ce8fb7af2559608948b362126e3..70e3183f94d106591bbba6ef4f0be10246247f4d 100644
--- a/appengine/findit/waterfall/test/identify_try_job_culprit_pipeline_test.py
+++ b/appengine/findit/waterfall/test/identify_try_job_culprit_pipeline_test.py
@@ -75,6 +75,18 @@ class IdentifyTryJobCulpritPipelineTest(testing.AppengineTestCase):
                     }
                 }
             }))
+    self.assertEqual(
+        'rev1',
+        IdentifyTryJobCulpritPipeline._GetFailedRevisionFromCompileResult(
+            {
+                'report': {
+                    'result': {
+                        'rev1': 'failed',
+                        'rev2': 'failed'
+                    },
+                    'culprit': 'rev1',
+                }
+            }))
 
   def testIdentifyCulpritForCompileTryJobNoCulprit(self):
     master_name = 'm'