Add a platform implementation of QuicTest and QuicTestWithParam

net/quic/platform/impl/quic_test_impl.cc

+// Copyright (c) 2017 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.
+
+#include "net/quic/platform/impl/quic_test_impl.h"
+
+#include "base/logging.h"
+#include "net/quic/platform/api/quic_flags.h"
+
+QuicFlagSaver::QuicFlagSaver() {
+#define QUIC_FLAG(type, flag, value)                                 \
+  CHECK_EQ(value, flag)                                              \
+      << "Flag set to an unexpected value.  A prior test is likely " \
+      << "setting a flag without using a QuicFlagSaver";
+#include "net/quic/core/quic_flags_list.h"
+#undef QUIC_FLAG
+}
+
+QuicFlagSaver::~QuicFlagSaver() {
+#define QUIC_FLAG(type, flag, value) flag = value;
+#include "net/quic/core/quic_flags_list.h"
+#undef QUIC_FLAG
+}