Remove unused files from webkitpy.

Tools/Scripts/webkitpy/common/net/regressionwindow.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
-# 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.
-
-
-# FIXME: This probably belongs in the buildbot module.
-class RegressionWindow(object):
-    def __init__(self, build_before_failure, failing_build, failing_tests=None):
-        self._build_before_failure = build_before_failure
-        self._failing_build = failing_build
-        self._failing_tests = failing_tests
-        self._revisions = None
-
-    def build_before_failure(self):
-        return self._build_before_failure
-
-    def failing_build(self):
-        return self._failing_build
-
-    def failing_tests(self):
-        return self._failing_tests
-
-    def revisions(self):
-        # Cache revisions to avoid excessive allocations.
-        if not self._revisions:
-            self._revisions = range(self._failing_build.revision(), self._build_before_failure.revision(), -1)
-            self._revisions.reverse()
-        return self._revisions