Remove a bunch of dead code from webkitpy

Tools/Scripts/webkitpy/tool/bot/expectedfailures.py

-# Copyright (c) 2011 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
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google Inc. nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-class ExpectedFailures(object):
-    def __init__(self):
-        self._failures = set()
-        self._is_trustworthy = True
-
-    @classmethod
-    def _has_failures(cls, results):
-        return bool(results and results.failing_tests())
-
-    @classmethod
-    def _should_trust(cls, results):
-        return bool(cls._has_failures(results) and results.failure_limit_count() and len(results.failing_tests()) < results.failure_limit_count())
-
-    def failures_were_expected(self, results):
-        if not self._is_trustworthy:
-            return False
-        if not self._should_trust(results):
-            return False
-        return set(results.failing_tests()) <= self._failures
-
-    def unexpected_failures_observed(self, results):
-        if not self._is_trustworthy:
-            return None
-        if not self._has_failures(results):
-            return None
-        return set(results.failing_tests()) - self._failures
-
-    def update(self, results):
-        if results:
-            self._failures = set(results.failing_tests())
-            self._is_trustworthy = self._should_trust(results)