Disable output buffering in devtools scripts.

mojo/devtools/common/mojo_test

 #!/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.
 
 """Test runner for Mojo application tests.
 
 TODO(vtl|msw): Add a way of specifying data dependencies.
 """
 
 import argparse
 import logging
 import sys
 import os.path
 
 from devtoolslib import apptest_dart
 from devtoolslib import apptest_gtest
 from devtoolslib import shell_arguments
 from devtoolslib import shell_config
+from devtoolslib.utils import disable_output_buffering
 
 _DESCRIPTION = """Runner for Mojo application tests.
 
 |test_list_file| has to be a valid Python program that sets a |tests| global
 variable, containing entries of the following form:
 
  {
    # Required URL for apptest.
    "test": "mojo:test_app_url",
    # Optional display name (otherwise the entry for "test" above is used).
@@ skipping 22 matching lines @@
 
 _logger = logging.getLogger()
 
 _CACHE_SERVICE_URL = 'mojo:url_response_disk_cache'
 _NETWORK_SERVICE_URL = 'mojo:network_service'
 _DART_STRICT_MODE_ARG = ('--args-for=mojo:dart_content_handler '
                          '--enable-strict-mode')
 
 
 def main():
+  disable_output_buffering()
   parser = argparse.ArgumentParser(
       formatter_class=argparse.RawDescriptionHelpFormatter,
       description=_DESCRIPTION)
   parser.add_argument("test_list_file", type=file,
                       help="a file listing apptests to run")
   shell_config.add_shell_arguments(parser)
 
   script_args, shell_args = parser.parse_known_args()
 
   try:
@@ skipping 23 matching lines @@
     test_type = test_dict.get("type", "gtest")
     test_args = test_dict.get("test-args", [])
     shell_args = test_dict.get("shell-args", []) + common_shell_args
     timeout = test_dict.get("timeout", 60)
     dart_strict_mode = test_dict.get("dart_strict_mode", True)
     if dart_strict_mode:
       shell_args.append(_DART_STRICT_MODE_ARG)
 
     _logger.info("Will start: %s" % test_name)
     print "Running %s...." % test_name,
-    sys.stdout.flush()
 
     if test_type == "dart":
       apptest_result = apptest_dart.run_dart_apptest(shell, shell_args, test,
                                                      test_args, timeout)
     elif test_type == "gtest":
       apptest_result = apptest_gtest.run_gtest_apptest(shell, shell_args, test,
                                                        test_args, timeout,
                                                        False)
     elif test_type == "gtest_isolated":
       apptest_result = apptest_gtest.run_gtest_apptest(shell, shell_args, test,
                                                        test_args, timeout,
                                                        True)
     else:
       apptest_result = False
       print "Unrecognized test type in %r" % test_dict
 
     print "Succeeded" if apptest_result else "Failed"
     _logger.info("Completed: %s" % test_name)
     if not apptest_result:
       succeeded = False
   return 0 if succeeded else 1
 
 if __name__ == '__main__':
   sys.exit(main())