webkitpy: Reworking test chunking for sharding.

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 1156 matching lines @@
         for test in self._expectations:
             if test.name and test.name in tests_to_skip:
                 test.warnings.append('%s:%s %s is also in a Skipped file.' % (test.filename, test.line_numbers, test.name))
 
         model = TestExpectationsModel(self._shorten_filename)
         for test_name in tests_to_skip:
             expectation_line = self._parser.expectation_for_skipped_test(test_name)
             model.add_expectation_line(expectation_line)
         self._model.merge_model(model)
 
+    def remove_tests(self, tests_to_remove):
+        for test in self._expectations:
+            if test.name and test.name in tests_to_remove:

[qyearsley, 2017/02/13 21:49:00]

I guess that self._expectations may contain TestExpectationLine objects for
blank lines and comments, which is why we want to check name?

Also, I think `test.name` is almost always the same as `test.path`, but it
theoretically might be different; probably doesn't matter here.

[mithro, 2017/02/14 00:40:03]

I'm following the `add_extra_skipped_tests` code above.

+                self.remove_expectation_line(test)
+
     def add_expectations_from_bot(self):
         # FIXME: With mode 'very-flaky' and 'maybe-flaky', this will show the expectations entry in the flakiness
         # dashboard rows for each test to be whatever the bot thinks they should be. Is this a good thing?
         bot_expectations = self._port.bot_expectations()
         model = TestExpectationsModel(self._shorten_filename)
         for test_name in bot_expectations:
             expectation_line = self._parser.expectation_line_for_test(test_name, bot_expectations[test_name])
 
             # Unexpected results are merged into existing expectations.
             model.add_expectation_line(expectation_line)
@@ skipping 15 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)))