events: Add a PRESUBMIT.py script to make sure the tries run enough tests.

ui/events/PRESUBMIT.py

Index: ui/events/PRESUBMIT.py
diff --git a/ui/events/PRESUBMIT.py b/ui/events/PRESUBMIT.py
new file mode 100644
index 0000000000000000000000000000000000000000..1b713b3b10b776efcfae543d9050fe1d64c0afd3
--- /dev/null
+++ b/ui/events/PRESUBMIT.py
@@ -0,0 +1,22 @@
+# Copyright 2014 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.
+
+"""Chromium presubmit script for src/ui/events
+
+See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
+for more details on the presubmit API built into gcl.
+"""
+
+def GetPreferredTrySlaves():
+  tests = set(['ash_unittests',
+               'aura_unittests',
+               'events_unittests',
+               'keyboard_unittests',
+               'views_unittests'])
+
+  return [('linux_aura', tests),
+          ('linux_chromeos', tests),
+          ('linux_chromeos_asan', tests),
+          ('win', tests),
+          ('win_rel', tests)]