Add PRESUBMIT checks for not required testharness expected files.

Tools/Scripts/check-testharness-expected-pass

+#!/usr/bin/env python
+#
+# Copyright 2014 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.
+
+"""Check if a LayoutTest expected file is a passing testharness result.
+
+The intent of this script is to identify expected files that are passing
+testharness.js results. Those files are not needed because the test
+infrastructure will read the output of testharness.js tests if there is no
+expected files."""
+
+
+import fileinput
+import sys
+
+from webkitpy.layout_tests.models import testharness_results
+
+paths = []
+
+for path in sys.argv[1:]:
+    content = open(path, 'r').read()
+    if testharness_results.is_testharness_output(content) and \
+       testharness_results.is_testharness_output_passing(content):
+        paths.append(path)
+
+if len(paths) > 0:
+    sys.stderr.write('* The following files are passing testharness results, they should be removed:\n ')
+    sys.stderr.write('\n '.join(paths))
+    sys.stderr.write('\n')
+    sys.exit("ERROR: found passing testharness results.")