Add a check to presubmit.py linting python and SCons files for trailing white...

tools/js2c.py

 #!/usr/bin/env python
 #
 # Copyright 2006-2008 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 273 matching lines @@
     lines = CompressScript(lines, do_jsmin)
     data = ToCArray(lines)
     id = (os.path.split(str(s))[1])[:-3]
     if delay: id = id[:-6]
     if delay:
       delay_ids.append((id, len(lines)))
     else:
       ids.append((id, len(lines)))
     source_lines.append(SOURCE_DECLARATION % { 'id': id, 'data': data })
     source_lines_empty.append(SOURCE_DECLARATION % { 'id': id, 'data': 0 })
-  
+
   # Build delay support functions
   get_index_cases = [ ]
   get_script_source_cases = [ ]
   get_script_name_cases = [ ]
 
   i = 0
   for (id, length) in delay_ids:
     native_name = "native %s.js" % id
     get_index_cases.append(GET_DELAY_INDEX_CASE % { 'id': id, 'i': i })
     get_script_source_cases.append(GET_DELAY_SCRIPT_SOURCE_CASE % {
@@ skipping 51 matching lines @@
 
 def main():
   natives = sys.argv[1]
   natives_empty = sys.argv[2]
   type = sys.argv[3]
   source_files = sys.argv[4:]
   JS2C(source_files, [natives, natives_empty], { 'TYPE': type })
 
 if __name__ == "__main__":
   main()