Put experimental extras through the same filters as non-experimental

tools/js2c.py

 #!/usr/bin/env python
 #
 # Copyright 2012 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 399 matching lines @@
     macro_file = macro_files[0]
 
   message_template_file = None
   message_template_files = filter(IsMessageTemplateFile, source_files)
   assert len(message_template_files) in [0, 1]
   if message_template_files:
     source_files.remove(message_template_files[0])
     message_template_file = message_template_files[0]
 
   filters = None
-  if native_type == "EXTRAS":
+  if native_type in ("EXTRAS", "EXPERIMENTAL_EXTRAS"):
     filters = BuildExtraFilterChain()
   else:
     filters = BuildFilterChain(macro_file, message_template_file)
 
   # Sort 'debugger' sources first.
   source_files = sorted(source_files,
                         lambda l,r: IsDebuggerFile(r) - IsDebuggerFile(l))
 
   source_files_and_contents = [(f, ReadFile(f)) for f in source_files]
 
@@ skipping 164 matching lines @@
   JS2C(args[2:],
        args[0],
        args[1],
        options.raw,
        options.startup_blob,
        options.js)
 
 
 if __name__ == "__main__":
   main()