Remove unused imports in webkitpy.

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

 # Copyright (C) 2009 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 14 matching lines @@
 # 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 StringIO
 import errno
 import hashlib
 import os
 import re
 
-from webkitpy.common.system import path
 
 
 class MockFileSystem(object):
     sep = '/'
     pardir = '..'
 
     def __init__(self, files=None, dirs=None, cwd='/'):
         """Initializes a "mock" filesystem that can be used to completely
         stub out a filesystem.
 
@@ skipping 434 matching lines @@
         return self.data.readline(length)
 
     def __iter__(self):
         return self.data.__iter__()
 
     def next(self):
         return self.data.next()
 
     def seek(self, offset, whence=os.SEEK_SET):
         self.data.seek(offset, whence)