Reland r159735 - support for test harness (text-only) tests w/o expected results.

Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py

 # Copyright (C) 2011 Google Inc. 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
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 30 matching lines @@
     root_output_dir = results_directory
     writer = TestResultWriter(filesystem, port, root_output_dir, test_name)
 
     if driver_output.error:
         writer.write_stderr(driver_output.error)
 
     for failure in failures:
         # FIXME: Instead of this long 'if' block, each failure class might
         # have a responsibility for writing a test result.
         if isinstance(failure, (test_failures.FailureMissingResult,
-                                test_failures.FailureTextMismatch)):
+                                test_failures.FailureTextMismatch,
+                                test_failures.FailureTestHarnessAssertion)):
             writer.write_text_files(driver_output.text, expected_driver_output.text)
             writer.create_text_diff_and_write_result(driver_output.text, expected_driver_output.text)
         elif isinstance(failure, test_failures.FailureMissingImage):
             writer.write_image_files(driver_output.image, expected_image=None)
         elif isinstance(failure, test_failures.FailureMissingImageHash):
             writer.write_image_files(driver_output.image, expected_driver_output.image)
         elif isinstance(failure, test_failures.FailureImageHashMismatch):
             writer.write_image_files(driver_output.image, expected_driver_output.image)
             writer.write_image_diff_files(driver_output.image_diff)
         elif isinstance(failure, (test_failures.FailureAudioMismatch,
@@ skipping 202 matching lines @@
             'diff_filename': self._output_testname(self.FILENAME_SUFFIX_IMAGE_DIFF),
             'prefix': self._output_testname(''),
         }
         self._filesystem.write_text_file(diffs_html_filename, html)
 
     def write_reftest(self, src_filepath):
         fs = self._filesystem
         dst_dir = fs.dirname(fs.join(self._root_output_dir, self._test_name))
         dst_filepath = fs.join(dst_dir, fs.basename(src_filepath))
         self._write_text_file(dst_filepath, fs.read_text_file(src_filepath))