Move gtest_prod_util.h out of webrtc/test tree.

webrtc/test/testsupport/gtest_prod_util.h

-/*
- *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef WEBRTC_TEST_TESTSUPPORT_GTEST_PROD_UTIL_H_
-#define WEBRTC_TEST_TESTSUPPORT_GTEST_PROD_UTIL_H_
-
-// Define our own version of FRIEND_TEST here rather than including
-// gtest_prod.h to avoid depending on any part of GTest in production code.
-#define FRIEND_TEST_WEBRTC(test_case_name, test_name)\
-friend class test_case_name##_##test_name##_Test
-
-// This file is a plain copy of Chromium's base/gtest_prod_util.h.
-//
-// This is a wrapper for gtest's FRIEND_TEST macro that friends
-// test with all possible prefixes. This is very helpful when changing the test
-// prefix, because the friend declarations don't need to be updated.
-//
-// Example usage:
-//
-// class MyClass {
-//  private:
-//   void MyMethod();
-//   FRIEND_TEST_ALL_PREFIXES(MyClassTest, MyMethod);
-// };
-#define FRIEND_TEST_ALL_PREFIXES(test_case_name, test_name) \
-  FRIEND_TEST_WEBRTC(test_case_name, test_name); \
-  FRIEND_TEST_WEBRTC(test_case_name, DISABLED_##test_name); \
-  FRIEND_TEST_WEBRTC(test_case_name, FLAKY_##test_name); \
-  FRIEND_TEST_WEBRTC(test_case_name, FAILS_##test_name)
-
-#endif  // WEBRTC_TEST_TESTSUPPORT_GTEST_PROD_UTIL_H_