Include Closure Compiler in CQ bots for various resource directories

ui/webui/resources/PRESUBMIT.py

Index: ui/webui/resources/PRESUBMIT.py
diff --git a/ui/webui/resources/PRESUBMIT.py b/ui/webui/resources/PRESUBMIT.py
new file mode 100644
index 0000000000000000000000000000000000000000..2ac87faf2b09787c19200dad102e395811d7661e
--- /dev/null
+++ b/ui/webui/resources/PRESUBMIT.py
@@ -0,0 +1,28 @@
+# 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 re
+
+
+def PostUploadHook(cl, change, output_api):
+  rietveld_obj = cl.RpcServer()
+  description = rietveld_obj.get_description(cl.issue)
+
+  existing_bots = (change.CQ_INCLUDE_TRYBOTS or '').split(';')
+  clean_bots = set(filter(None, map(lambda s: s.strip(), existing_bots)))
+  new_bots = clean_bots | set(['tryserver.chromium.linux:closure_compilation'])
+  new_tag = 'CQ_INCLUDE_TRYBOTS=%s' % ';'.join(new_bots)
+
+  if clean_bots:
+    tag_reg = '^CQ_INCLUDE_TRYBOTS=.*$'
+    new_description = re.sub(tag_reg, new_tag, description, flags=re.M | re.I)
+  else:
+    new_description = description + '\n' + new_tag
+
+  if new_description == description:
+    return []
+
+  rietveld_obj.update_description(cl.issue, new_description)
+  return [output_api.PresubmitNotifyResult(
+      'Automatically added optional Closure bots to run on CQ.')]