Create the harness and shell of update_test_expectations

third_party/WebKit/Tools/Scripts/update-test-expectations

+#!/usr/bin/python
+#
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import sys
+
+from webkitpy.common import host
+from webkitpy.layout_tests import update_test_expectations
+from webkitpy.layout_tests.layout_package.bot_test_expectations import BotTestExpectationsFactory
+
+if __name__ == "__main__":
+    _host = host.Host()
+    return_code = update_test_expectations.main(_host,
+                                                BotTestExpectationsFactory(_host.builders),
+                                                sys.argv[1:])
+    sys.exit(return_code)