Have webkit-patch rebaseline-test update test_expectations.txt

Have webkit-patch rebaseline-test update test_expectations.txt
https://bugs.webkit.org/show_bug.cgi?id=81054

Reviewed by Dirk Pranke.

This will allow us to use the All Failures tab in garden-o-matic
to rebaseline tests without making test_expectations.txt stale.

It's conservative and only removes lines if the test is
not flaky and fails in a way the rebaseline would fix (e.g.
CRASH/TIMEOUT will not be touched).

* Scripts/webkitpy/layout_tests/models/test_expectations.py:
(TestExpectations.remove_configuration_from_test):
* Scripts/webkitpy/layout_tests/models/test_expectations_unittest.py:
(RemoveConfigurationsTest):
(RemoveConfigurationsTest.test_remove):
(test_remove_line):
* Scripts/webkitpy/tool/commands/rebaseline.py:
(RebaselineTest._is_supported_port):
(RebaselineTest):
(RebaselineTest._update_expectations_file):
(RebaselineTest._rebaseline_test_and_update_expectations):
(RebaselineTest.execute):
* Scripts/webkitpy/tool/commands/rebaseline_unittest.py:
(TestRebaseline.test_rebaseline_updates_expectations_file):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@110783 268f45cc-cd09-0410-ab3c-d52691b4dbfc