Remove sync_wpt and add wpt-export to replace it.

third_party/WebKit/Tools/Scripts/wpt-export

Index: third_party/WebKit/Tools/Scripts/wpt-export
diff --git a/third_party/WebKit/Tools/Scripts/wpt-export b/third_party/WebKit/Tools/Scripts/wpt-export
new file mode 100755
index 0000000000000000000000000000000000000000..f19ddabe409abe8dd48cbaac109697ad30bb4b85
--- /dev/null
+++ b/third_party/WebKit/Tools/Scripts/wpt-export
@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+# Copyright 2017 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.
+
+"""Exports local changes to web-platform-tests in Chromium to upstream repo.
+
+This script checks LayoutTests/external/wpt for changes that can be exported,
+then creates a patch, and creates and lands a pull request for the upstream
+repository.
+"""
+
+import argparse
+import logging
+
+from webkitpy.common.host import Host
+from webkitpy.w3c.test_exporter import TestExporter
+from webkitpy.w3c.wpt_github import WPTGitHub
+
+
+_log = logging.getLogger(__name__)
+
+
+def main():
+    logging.basicConfig(level=logging.INFO, format='%(message)s')
+
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        '--dry-run', action='store_true',
+        help='See what would be done without actually creating or merging '
+             'any pull requests.')
+    args = parser.parse_args()
+
+    host = Host()
+    wpt_github = WPTGitHub(host)
+    test_exporter = TestExporter(host, wpt_github, dry_run=args.dry_run)
+
+    test_exporter.run()
+
+
+if __name__ == '__main__':
+    main()