Remove Skia's forked buildbot code

slave/skia_slave_scripts/chrome_drt_canary_pretest.py

Index: slave/skia_slave_scripts/chrome_drt_canary_pretest.py
diff --git a/slave/skia_slave_scripts/chrome_drt_canary_pretest.py b/slave/skia_slave_scripts/chrome_drt_canary_pretest.py
deleted file mode 100644
index d1462b21cba0e25dc2a7e4a925608d18243119ec..0000000000000000000000000000000000000000
--- a/slave/skia_slave_scripts/chrome_drt_canary_pretest.py
+++ /dev/null
@@ -1,21 +0,0 @@
-#!/usr/bin/env python
-# Copyright (c) 2013 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-""" Run this before running any tests. """
-
-from build_step import BuildStep
-import sys
-
-
-class ChromeDRTCanaryPreTest(BuildStep):
-  def _Run(self):
-    self._flavor_utils.CreateCleanHostDirectory(
-        self._flavor_utils.baseline_dir)
-    self._flavor_utils.CreateCleanHostDirectory(
-        self._flavor_utils.result_dir)
-
-
-if '__main__' == __name__:
-  sys.exit(BuildStep.RunBuildStep(ChromeDRTCanaryPreTest))