[Findit] Add two more gtest command line switches.

appengine/findit/waterfall/trigger_base_swarming_task_pipeline.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 copy
 import logging
 import time
 
 from common.http_client_appengine import HttpClientAppengine as HttpClient
 from common.pipeline_wrapper import BasePipeline
@@ skipping 22 matching lines @@
     # Make a copy of the referred request and drop or overwrite some fields.
     new_request = copy.deepcopy(ref_request)
     new_request.name = self._GetSwarmingTaskName(ref_task_id)
     new_request.parent_task_id = ''
     new_request.user = ''
 
     # To force a fresh re-run and ignore cached result of any equivalent run.
     new_request.idempotent = False
 
     # Set the gtest_filter to run the given tests only.
+    # Remove existing test filter first.
+    new_request.extra_args = [
+        a for a in new_request.extra_args if (
+            not a.startswith('--gtest_filter') and
+            not a.startswith('--test-launcher-filter-file'))
+    ]
+    new_request.extra_args.append('--gtest_filter=%s' % ':'.join(tests))
     new_request.extra_args.append('--gtest_repeat=%s' % iterations)
     new_request.extra_args.append('--test-launcher-retry-limit=0')
-    new_request.extra_args = [
-        a for a in new_request.extra_args if not a.startswith('--gtest_filter')
-    ]
-    new_request.extra_args.append('--gtest_filter=%s' % ':'.join(tests))
+
+    # Also rerun disabled tests. Scenario: the test was disabled before Findit
+    # runs any analysis. One possible case:
+    #   1. A gtest became flaky on CQ, but Findit was not automatically
+    #      triggered to run any analysis because:
+    #      * the test is not flaky enough
+    #      * chromium-try-flakes has filed/updated too many bugs
+    #   2. The test got disabled, but no culprit was identified.
+    #   3. Some developer starts the investigation and requests Findit to
+    #      analyze the flaky test.
+    #   4. Findit picks the latest Waterfall build of the matching configuration
+    #      for the CQ build in which the flaky test is found.
+    #   5. In the picked Waterfall build, the test is already disabled.
+    new_request.extra_args.append('--gtest_also_run_disabled_tests')
 
     # Remove the env setting for sharding.
     sharding_settings = ['GTEST_SHARD_INDEX', 'GTEST_TOTAL_SHARDS']
     new_request.env = [
         e for e in new_request.env if e['key'] not in sharding_settings
     ]
 
     # Reset tags for searching and monitoring.
     ref_name = swarming_util.GetTagValue(ref_request.tags, 'name')
     new_request.tags = []
@@ skipping 127 matching lines @@
       swarming_task.error = error
     else:
       logging.info('A Swarming task was triggered:%s', task_id)
 
     swarming_task.put()
 
     # Call the hook function after the task is triggered.
     self._OnTaskTriggered()
 
     return task_id