clang/win: Try to fix 64-bit build after https://codereview.chromium.org/1261953003.

sandbox/win/src/process_mitigations_test.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/strings/stringprintf.h"
 #include "base/win/scoped_handle.h"
 
 #include "base/win/windows_version.h"
 #include "sandbox/win/src/nt_internals.h"
 #include "sandbox/win/src/process_mitigations.h"
@@ skipping 12 matching lines @@
     PBOOL permanent);
 
 typedef BOOL (WINAPI *GetProcessMitigationPolicyFunction)(
     HANDLE process,
     PROCESS_MITIGATION_POLICY mitigation_policy,
     PVOID buffer,
     SIZE_T length);
 
 GetProcessMitigationPolicyFunction get_process_mitigation_policy;
 
+#if !defined(_WIN64)
 bool CheckWin8DepPolicy() {
   PROCESS_MITIGATION_DEP_POLICY policy = {};
   if (!get_process_mitigation_policy(::GetCurrentProcess(), ProcessDEPPolicy,
                                      &policy, sizeof(policy))) {
     return false;
   }
   return policy.Enable && policy.Permanent;
 }
+#endif  // !defined(_WIN64)
 
 #if defined(NDEBUG)
 bool CheckWin8AslrPolicy() {
   PROCESS_MITIGATION_ASLR_POLICY policy = {};
   if (!get_process_mitigation_policy(::GetCurrentProcess(), ProcessASLRPolicy,
                                      &policy, sizeof(policy))) {
      return false;
   }
   return policy.EnableForceRelocateImages && policy.DisallowStrippedImages;
 }
@@ skipping 190 matching lines @@
   EXPECT_EQ(policy->SetProcessMitigations(MITIGATION_WIN32K_DISABLE),
             SBOX_ALL_OK);
   EXPECT_EQ(policy->AddRule(sandbox::TargetPolicy::SUBSYS_WIN32K_LOCKDOWN,
                             sandbox::TargetPolicy::FAKE_USER_GDI_INIT, NULL),
             sandbox::SBOX_ALL_OK);
   EXPECT_EQ(SBOX_TEST_SUCCEEDED, runner.RunTest(L"CheckWin8Lockdown"));
 }
 
 }  // namespace sandbox