Fix pylint unused-* warnings in webkitpy/tool.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaselineserver.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.
 
 """Starts a local HTTP server which displays layout test failures (given a test
 results directory), provides comparisons of expected and actual results (both
 images and text) and allows one-click rebaselining of tests."""
 
-from webkitpy.common import system
 from webkitpy.common.host import Host
 from webkitpy.common.net.layouttestresults import for_each_test, JSONTestResult
 from webkitpy.layout_tests.layout_package import json_results_generator
 from webkitpy.tool.commands.abstractlocalservercommand import AbstractLocalServerCommand
 from webkitpy.tool.servers.rebaselineserver import get_test_baselines, RebaselineHTTPServer, STATE_NEEDS_REBASELINE
 
 
 class TestConfig(object):
 
     def __init__(self, test_port, layout_tests_directory, results_directory, platforms, host):
@@ skipping 49 matching lines @@
         self._gather_baselines(results_json)
 
         return {
             'test_config': self._test_config,
             "results_json": results_json,
             "platforms_json": {
                 'platforms': platforms,
                 'defaultPlatform': port.name(),
             },
         }