Remove thirdparty/unittest2 from webkitpy and require python2.7.

Tools/Scripts/webkitpy/style/filereader_unittest.py

 # Copyright (C) 2010 Chris Jerdonek (cjerdonek@webkit.org)
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1.  Redistributions of source code must retain the above copyright
 #     notice, this list of conditions and the following disclaimer.
 # 2.  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.
 #
 # THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-import webkitpy.thirdparty.unittest2 as unittest
+import unittest
 
 from webkitpy.common.system.filesystem import FileSystem
 from webkitpy.common.system.logtesting import LoggingTestCase
 from webkitpy.style.checker import ProcessorBase
 from webkitpy.style.filereader import TextFileReader
 
 
 class TextFileReaderTest(LoggingTestCase):
 
     class MockProcessor(ProcessorBase):
@@ skipping 112 matching lines @@
 
         self._file_reader.process_paths([dir, file_path1])
         processed = [(['bar'], file_path2, None),
                      (['foo'], file_path1, None)]
         self._assert_file_reader(processed, 2)
 
     def test_count_delete_only_file(self):
         self._file_reader.count_delete_only_file()
         delete_only_file_count = self._file_reader.delete_only_file_count
         self.assertEqual(delete_only_file_count, 1)