Generate constants for HTTP status codes and reason phrases using macro.

net/http/http_status_code_unittest.cc

+// 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.
+
+#include "net/http/http_status_code.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace {
+
+TEST(HttpStatusCode, OK) {
+  EXPECT_EQ(200, HTTP_OK);
+  EXPECT_STREQ("OK", GetHttpReasonPhrase(HTTP_OK));
+}
+
+}  // namespace
+
+}  // namespace net