Remove remaining unused imports in webkitpy.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.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
@@ skipping 11 matching lines @@
 # 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.
 
 """Windows implementation of the Port interface."""
 
 import errno
-import os
 import logging
 
 try:
     import _winreg
 except ImportError as e:
     _winreg = None
     WindowsError = Exception  # this shuts up pylint.
 
 from webkitpy.layout_tests.breakpad.dump_reader_win import DumpReaderWin
 from webkitpy.layout_tests.models import test_run_results
@@ skipping 197 matching lines @@
         return result
 
     def look_for_new_crash_logs(self, crashed_processes, start_time):
         if self.get_option('disable_breakpad'):
             return None
         return self._dump_reader.look_for_new_crash_logs(crashed_processes, start_time)
 
     def clobber_old_port_specific_results(self):
         if not self.get_option('disable_breakpad'):
             self._dump_reader.clobber_old_results()