Add some code to ensure that stdout is always flushed and closed to help debug layout tests hanging…

scripts/slave/chromium/layout_test_wrapper.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """A wrapper script to run layout tests on the buildbots.
 
 Runs the run-webkit-tests script found in third_party/WebKit/Tools/Scripts above
 this script. For a complete list of command-line options, pass '--help' on the
 command line.
@@ skipping 132 matching lines @@
   # directory from previous test runs (i.e.- from crashes or unittest leaks).
   slave_utils.RemoveChromeTemporaryFiles()
 
   try:
     if options.enable_pageheap:
       slave_utils.SetPageHeap(build_dir, dumprendertree_exe, True)
     # Run the the tests
     return slave_utils.RunPythonCommandInBuildDir(build_dir, options.target,
                                                   command)
   finally:
+    if 'win_chromium_rel_ng' in sys.argv:
+      print 'layout_test_wrapper calling stdout.flush()'
+      try:
+        sys.stdout.flush()
+      finally:
+        print 'layout_test_wrapper calling stdout.close()'
+        sys.stdout.close()
     if options.enable_pageheap:
       slave_utils.SetPageHeap(build_dir, dumprendertree_exe, False)
 
     if options.json_test_results:
       results_dir = options.results_directory
       results_json = os.path.join(results_dir, "failing_results.json")
 
       # If the json results file was not produced, then we produce no output
       # file too and rely on a recipe to handle this as invalid result.
       if os.path.isfile(results_json):
@@ skipping 99 matching lines @@
   options, args = option_parser.parse_args()
   options.build_dir = build_directory.GetBuildOutputDirectory()
 
   # Disable pageheap checking except on Windows.
   if sys.platform != 'win32':
     options.enable_pageheap = False
   return layout_test(options, args)
 
 if '__main__' == __name__:
   sys.exit(main())