Create test expectations line automatically from failing test results

third_party/WebKit/Tools/Scripts/update-w3c-test-expections

Index: third_party/WebKit/Tools/Scripts/update-w3c-test-expections
diff --git a/third_party/WebKit/Tools/Scripts/update-w3c-test-expections b/third_party/WebKit/Tools/Scripts/update-w3c-test-expections
new file mode 100755
index 0000000000000000000000000000000000000000..f36c8a2d3c5a4a071dd4b2b4c3c09c4fed05f7bf
--- /dev/null
+++ b/third_party/WebKit/Tools/Scripts/update-w3c-test-expections
@@ -0,0 +1,18 @@
+#!/usr/bin/env 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.common.checkout.scm.git import Git
+from webkitpy.w3c.update_w3c_test_expectations import main
+
+if __name__ == "__main__":
+    host = host.Host()
+    host.initialize_scm()
+    port = host.port_factory.get()
+    return_code = main(host, port)
+
+sys.exit(return_code)