Remove unused imports in webkitpy.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/run_webkit_tests.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 # Copyright (C) 2010 Gabor Rapcsanyi (rgabor@inf.u-szeged.hu), University of Szeged
 # Copyright (C) 2011 Apple 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.
@@ skipping 17 matching lines @@
 # (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 logging
 import optparse
 import os
 import sys
 import traceback
 
 from webkitpy.common.host import Host
-from webkitpy.common.system.executive import Executive
 from webkitpy.layout_tests.controllers.manager import Manager
 from webkitpy.layout_tests.models import test_run_results
 from webkitpy.layout_tests.port.factory import configuration_options, platform_options
 from webkitpy.layout_tests.views import buildbot_results
 from webkitpy.layout_tests.views import printing
 from webkitpy.layout_tests.generate_results_dashboard import DashBoardGenerator
 
 _log = logging.getLogger(__name__)
 
 
@@ skipping 523 matching lines @@
             _log.debug("\t%s" % process)
 
         return run_details
 
     finally:
         printer.cleanup()
 
 if __name__ == '__main__':
     exit_code = main(sys.argv[1:], sys.stdout, sys.stderr)
     sys.exit(exit_code)