Instead of a large 'if' block, each failure class should write it's own result in test_result_writer.py
https://bugs.webkit.org/show_bug.cgi?id=124714

Patch by Dániel Bátyai <Batyai.Daniel@stud.u-szeged.hu> on 2013-12-02
Reviewed by Ryosuke Niwa.

* Scripts/webkitpy/layout_tests/controllers/test_result_writer.py:
(write_test_result):
* Scripts/webkitpy/layout_tests/models/test_failures.py:
(TestFailure.write_failure):
(FailureText):
(FailureText.write_failure):
(FailureAudio):
(FailureAudio.write_failure):
(FailureCrash.write_failure):
(FailureMissingResult):
(FailureTextMismatch):
(FailureMissingImageHash.write_failure):
(FailureMissingImage.write_failure):
(FailureImageHashMismatch.write_failure):
(FailureReftestMismatch.write_failure):
(FailureReftestMismatchDidNotOccur.write_failure):
(FailureMissingAudio):
(FailureAudioMismatch):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159978 268f45cc-cd09-0410-ab3c-d52691b4dbfc