Remove several unneeded modules from webkitpy.common.

Tools/Scripts/webkitpy/common/editdistance_unittest.py

-# 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
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google Inc. nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-import unittest
-
-from webkitpy.common.editdistance import edit_distance
-
-
-class EditDistanceTest(unittest.TestCase):
-    def test_edit_distance(self):
-        self.assertEqual(edit_distance('', 'aa'), 2)
-        self.assertEqual(edit_distance('aa', ''), 2)
-        self.assertEqual(edit_distance('a', 'ab'), 1)
-        self.assertEqual(edit_distance('ab', 'a'), 1)
-        self.assertEqual(edit_distance('ab', 'aa'), 1)
-        self.assertEqual(edit_distance('aa', 'ab'), 1)
-        self.assertEqual(edit_distance('abd', 'abcdef'), 3)
-        self.assertEqual(edit_distance('abcdef', 'abd'), 3)