Add PRESBUMIT hook to automatically add obbs_fyi bots to tools/perf/core changes

Cq-Include-Trybots: master.tryserver.chromium.perf:obbs_fyi
Change-Id: I32a057c4bb0b9c443b4518d36acf6e2fd6a73b3f

NOTRY=true  # test covered by PRESUBMIT

Change-Id: I32a057c4bb0b9c443b4518d36acf6e2fd6a73b3f
Reviewed-on: https://chromium-review.googlesource.com/1122487Reviewed-by: Emily Hanley <eyaich@chromium.org>
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#571899}

tools/perf/core/PRESUBMIT.py

+# Copyright 2018 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.
+
+def PostUploadHook(cl, change, output_api):
+  """git cl upload will call this hook after the issue is created/modified.
+
+  This hook modifies the CL description in order to run extra perf trybot
+  tests (in particular, obbs fyi tests) in addition
+  to the regular CQ try bots. We don't have enough hardware to run
+  against all tools/perf/ commits, but should be run against changes
+  likely to affect these tests.
+  """
+  del change  # unused
+  return output_api.EnsureCQIncludeTrybotsAreAdded(
+    cl,
+    [
+      'master.tryserver.chromium.perf:obbs_fyi',
+    ],
+    'Automatically added optional perf trybot tests to run on CQ.')