Make NeedsRebaseline illegal in layout_test TestExpectations for now.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/test_expectations.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 152 matching lines @@
         expectation_line.matching_configurations = self._test_configuration_converter.to_config_set(
             parsed_specifiers, expectation_line.warnings)
 
     def _lint_line(self, expectation_line):
         expectations = [expectation.lower() for expectation in expectation_line.expectations]
         if not expectation_line.bugs and self.WONTFIX_MODIFIER not in expectations:
             expectation_line.warnings.append(self.MISSING_BUG_WARNING)
         if self.REBASELINE_MODIFIER in expectations:
             expectation_line.warnings.append('REBASELINE should only be used for running rebaseline.py. Cannot be checked in.')
 
+        # TODO(crbug.com/603753) - Don't let NeedsRebaseline be checked in while the auto-rebaseline-bot is down.
+        if self.NEEDS_REBASELINE_MODIFIER in expectations:
+            expectation_line.warnings.append('NeedsRebaseline is broken at the moment. See crbug.com/603753.')
+
         if self.NEEDS_REBASELINE_MODIFIER in expectations or self.NEEDS_MANUAL_REBASELINE_MODIFIER in expectations:
             for test in expectation_line.matching_tests:
                 if self._port.reference_files(test):
                     expectation_line.warnings.append('A reftest cannot be marked as NeedsRebaseline/NeedsManualRebaseline')
 
         specifiers = [specifier.lower() for specifier in expectation_line.specifiers]
         if (self.REBASELINE_MODIFIER in expectations or self.NEEDS_REBASELINE_MODIFIER in expectations) and ('debug' in specifiers or 'release' in specifiers):
             expectation_line.warnings.append('A test cannot be rebaselined for Debug/Release.')
 
     def _parse_expectations(self, expectation_line):
@@ skipping 981 matching lines @@
             # If reconstitute_only_these is an empty list, we want to return original_string.
             # So we need to compare reconstitute_only_these to None, not just check if it's falsey.
             if reconstitute_only_these is None or expectation_line in reconstitute_only_these:
                 return expectation_line.to_string(test_configuration_converter)
             return expectation_line.original_string
 
         def nones_out(expectation_line):
             return expectation_line is not None
 
         return "\n".join(filter(nones_out, map(serialize, expectation_lines)))