[libfuzzer] support of custom libfuzzer options via .options file.

testing/libfuzzer/tests/check_fuzzer_config.py

+#!/usr/bin/python2
+# Copyright 2015 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.
+
+# Script that prints out "option=value" from the config file. Used for testing.
+
+import ConfigParser
+import os
+import sys
+
+OPTIONS_SECTION_LIBFUZZER = 'libfuzzer'
+
+config_path = os.path.join(os.path.dirname(sys.argv[0]), sys.argv[1])
+fuzzer_config = ConfigParser.ConfigParser()
+fuzzer_config.read(config_path)
+
+if not fuzzer_config.has_section(OPTIONS_SECTION_LIBFUZZER):
+  sys.exit(-1)
+
+for option_name in fuzzer_config.options(OPTIONS_SECTION_LIBFUZZER):

[Oliver Chang, 2016/02/29 18:53:50]

nit: can you use .items() here?

[mmoroz, 2016/03/01 12:35:20]

Yes, it would be better, thanks!

Done.

+  option_value = fuzzer_config.get(OPTIONS_SECTION_LIBFUZZER, option_name)
+  sys.stdout.write('%s=%s\n\r' % (option_name, option_value))

[Oliver Chang, 2016/02/29 18:53:50]

Why do you need the \r here?

[mmoroz, 2016/03/01 12:35:20]

I saw that existing test from Mike uses '\n\r' to split lines from script's
output and decided that may be there is any reasonable point for this. He used
|print|, so it could matter for some platforms. Since I'm using
|sys.stdout.write()| I can leave only '\n' in both places. Thanks!

Done.