Remove sandbox on Windows.

sandbox/win/tests/unit_tests/unit_tests.cc

-// Copyright (c) 2011 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 "base/bind.h"
-#include "base/test/launcher/unit_test_launcher.h"
-#include "base/test/test_suite.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-int wmain(int argc, wchar_t **argv) {
-  if (argc >= 2) {
-    if (0 == _wcsicmp(argv[1], L"-child"))
-      // This instance is a child, not the test.
-      return 0;
-  }
-
-  base::TestSuite test_suite(argc, argv);
-  return base::LaunchUnitTests(
-      argc,
-      argv,
-      false,
-      base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));
-}