Add a PRESUBMIT in //sandbox/linux to add extra CQ bots for Seccomp changes.

Forgetting to test compilation on Android {arm,arm64,x86,x64,mips} has
repeatedly caused internal/downstream breakages in the past. This should
add a modicum of sanity.

Change-Id: Ibc43d4f118c0ccfa532240d00b2f799722df9700
Reviewed-on: https://chromium-review.googlesource.com/797332Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520177}

sandbox/linux/PRESUBMIT.py

+# Copyright 2017 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 will add extra trybot coverage for non-default Android architectures
+  that have a history of breaking with Seccomp changes.
+  """
+  def affects_seccomp(f):
+    seccomp_paths = [
+        'bpf_dsl/',
+        'seccomp-bpf/',
+        'seccomp-bpf-helpers/',
+        'system_headers/',
+        'tests/'
+        ]
+    # If the file path contains any of the above fragments, it affects
+    # the Seccomp implementation.
+    affected_any = map(lambda sp: sp in f.LocalPath(), seccomp_paths)
+    return reduce(lambda a, b: a or b, affected_any)
+
+  if not change.AffectedFiles(file_filter=affects_seccomp):
+    return []
+
+  return output_api.EnsureCQIncludeTrybotsAreAdded(
+      cl,
+      [
+        'master.tryserver.chromium.android:android_arm64_dbg_recipe',
+        'master.tryserver.chromium.android:android_compile_mips_dbg',
+        'master.tryserver.chromium.android:android_compile_x64_dbg',
+        'master.tryserver.chromium.android:android_compile_x86_dbg',
+      ],
+      'Automatically added Android multi-arch compile bots to run on CQ.')