Remove all unused variables.

third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_unittest.py

 # vim: set fileencoding=utf-8 :
 # Copyright (C) 2010 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
@@ skipping 241 matching lines @@
             # Clean up in case the test failed and we did create the
             # directory.
             if os.path.exists(sub_dir):
                 os.rmdir(sub_dir)
 
     def test_read_and_write_text_file(self):
         fs = FileSystem()
         text_path = None
 
         unicode_text_string = u'\u016An\u012Dc\u014Dde\u033D'
-        hex_equivalent = '\xC5\xAA\x6E\xC4\xAD\x63\xC5\x8D\x64\x65\xCC\xBD'
         try:
             text_path = tempfile.mktemp(prefix='tree_unittest_')
             file = fs.open_text_file_for_writing(text_path)
             file.write(unicode_text_string)
             file.close()
 
             file = fs.open_text_file_for_reading(text_path)
             read_text = file.read()
             file.close()
 
@@ skipping 47 matching lines @@
         fs = FileSystem()
         self.assertTrue(fs.remove('filename', remove_with_exception))
         self.assertEqual(-1, RealFileSystemTest._remove_failures)
 
     def test_sep(self):
         fs = FileSystem()
 
         self.assertEqual(fs.sep, os.sep)
         self.assertEqual(fs.join("foo", "bar"),
                          os.path.join("foo", "bar"))