Remove unused imports in webkitpy with using autoflake.

third_party/WebKit/Tools/Scripts/webkitpy/common/system/path.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 12 matching lines @@
 # 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.
 
 """generic routines to convert platform-specific paths to URIs."""
 
 import atexit
 import subprocess
-import sys
 import threading
 import urllib
 
 
 def abspath_to_uri(platform, path):
     """Converts a platform-specific absolute path to a file: URL."""
     return "file:" + _escape(_convert_path(platform, path))
 
 
 def cygpath(path):
@@ skipping 82 matching lines @@
 
 
 def _winpath_to_uri(path):
     """Converts a window absolute path to a file: URL."""
     return "///" + path.replace("\\", "/")
 
 
 def _unixypath_to_uri(path):
     """Converts a unix-style path to a file: URL."""
     return "//" + path