Disable output buffering in devtools scripts.

mojo/devtools/common/mojo_run

 #!/usr/bin/env python
 # 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.
 
 import argparse
 import logging
 import sys
 
 from devtoolslib import shell_arguments
 from devtoolslib import shell_config
+from devtoolslib.utils import disable_output_buffering
 
 _DESCRIPTION = """Runner for Mojo applications.
 
 Any arguments not recognized by the script will be passed on as shell arguments.
 
 Important shell arguments include:
   "--args-for=<mojo-app-url> <arguments>"
   "--content-handlers=<handlers>"
   "--disable-cache"
   "--enable-multiprocess"
@@ skipping 19 matching lines @@
 
   Returns:
     Arguments that need to be appended to the shell argument list in order to
     run with the debugger.
   """
   shell.forward_host_port_to_shell(_MOJO_DEBUGGER_PORT)
   return ['%s %d' % (_DEBUGGER_URL, _MOJO_DEBUGGER_PORT)]
 
 
 def main():
+  disable_output_buffering()
   logging.basicConfig()
 
   parser = argparse.ArgumentParser(
       formatter_class=argparse.RawDescriptionHelpFormatter,
       description=_DESCRIPTION)
   shell_config.add_shell_arguments(parser)
 
   parser.add_argument('--embed', type=str,
                       help='Url to be embedded in the window manager.')
   parser.add_argument('--debugger', action="store_true",
@@ skipping 20 matching lines @@
 
   if script_args.verbose:
     print "Shell arguments: " + str(shell_args)
 
   shell.run(shell_args)
   return 0
 
 
 if __name__ == "__main__":
   sys.exit(main())