Add top level app element

PRESUBMIT.py

 # Copyright 2013 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Top-level presubmit script for LUCI.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
@@ skipping 11 matching lines @@
     r'.*? that can be found in the LICENSE file\.(?: \*/)?\n'
   ) % {
     'year': years_re,
   }
   return license_header
 
 
 def CommonChecks(input_api, output_api):
   excluded = [
     r'.+-build\.(js|html)$',
+    r'.+/build/.+(js|html)$',
     r'/test',
     r'.+_pb2\.py$',
     r'.*third_party.*',
   ]
   return input_api.canned_checks.PanProjectChecks(
       input_api, output_api,
       excluded_paths=excluded,
       owners_check=False,
       license_header=header(input_api))
 
 
 def CheckChangeOnUpload(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def CheckChangeOnCommit(input_api, output_api):
   return CommonChecks(input_api, output_api)