Disable output buffering in devtools scripts.

mojo/devtools/common/mojo_benchmark

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 """Runner for Mojo application benchmarks."""
 
 import argparse
 import logging
 import numpy
 import sys
 import time
 
 from devtoolslib import benchmark
 from devtoolslib import perf_dashboard
 from devtoolslib import shell_arguments
 from devtoolslib import shell_config
+from devtoolslib.utils import disable_output_buffering
 
 
 _DESCRIPTION = """Runner for Mojo application benchmarks.
 
 |benchmark_list_file| has to be a valid Python program that sets a |benchmarks|
 dictionary. For description of the required format see
 https://github.com/domokit/devtools/blob/master/docs/mojo_benchmark.md .
 """
 
 _logger = logging.getLogger()
@@ skipping 110 matching lines @@
     cast_value = int(value)
   except ValueError:
     raise argparse.ArgumentTypeError('value is not a positive integer')
 
   if cast_value < 1:
     raise argparse.ArgumentTypeError('value is not a positive integer')
   return cast_value
 
 
 def main():
+  disable_output_buffering()
   parser = argparse.ArgumentParser(
       formatter_class=argparse.RawDescriptionHelpFormatter,
       description=_DESCRIPTION)
   parser.add_argument('benchmark_list_file', type=file,
                       help='a file listing benchmarks to run')
   parser.add_argument('--aggregate', type=_argparse_aggregate_type,
                       help='aggregate results over multiple runs. The value '
                       'has to be a positive integer indicating the number of '
                       'runs.')
   parser.add_argument('--save-all-traces', action='store_true',
@@ skipping 64 matching lines @@
                                            variant_results[variant_name],
                                            variant_spec['measurements'],
                                            script_args)
         if not upload_succeeded:
           exit_code = 1
 
   return exit_code
 
 if __name__ == '__main__':
   sys.exit(main())